smb.conf

smb.conf
Name
smb.conf — The configuration file for the Samba suite
SYNOPSIS
The
smb.conf
file is a configuration file for the Samba suite.
smb.conf
contains runtime configuration information for the Samba programs. The
complete description of the file format and possible parameters held within are here for reference purposes.
HOW CONFIGURATION CHANGES ARE APPLIED
The Samba suite includes a number of different programs. Some of them operate in a client mode, others are
server daemons that provide various services to its clients. The
smb.conf
file is processed in the following way:
The Samba suite's client applications read their configuration only once. Any changes made after start aren't
reflected in the context of already running client code.
The Samba suite's server daemons reload their configuration when requested. However, already active connections
do not change their configuration. More detailed information can be found in
smbd
(8)
and
winbindd
(8)
manual pages.
To request Samba server daemons to refresh their configuration, please use
smbcontrol
(1)
utility.
FILE FORMAT
The file consists of sections and parameters. A section begins with the name of the section in square brackets
and continues until the next section begins. Sections contain parameters of the form:
name
value
The file is line-based - that is, each newline-terminated line represents either a comment, a section name or
a parameter.
Section and parameter names are not case sensitive.
Only the first equals sign in a parameter is significant. Whitespace before or after the first equals sign is
discarded. Leading, trailing and internal whitespace in section and parameter names is irrelevant. Leading
and trailing whitespace in a parameter value is discarded. Internal whitespace within a parameter value is
retained verbatim.
Any line beginning with a semicolon (
) or a hash (
character is ignored, as are lines containing only whitespace.
Any line ending in a
is continued on the next line in the customary UNIX fashion.
The values following the equals sign in parameters are all either a string (no quotes needed) or a boolean,
which may be given as yes/no, 1/0 or true/false. Case is not significant in boolean values, but is preserved
in string values. Some items such as create masks are numeric.
SECTION DESCRIPTIONS
Each section in the configuration file (except for the [global] section) describes a shared resource (known as
share
). The section name is the name of the shared resource and the parameters within the
section define the shares attributes.
There are three special sections, [global], [homes] and [printers], which are described under
special sections
. The following notes apply to ordinary section descriptions.
A share consists of a directory to which access is being given plus a description of the access rights
which are granted to the user of the service. Some housekeeping options are also specifiable.
Sections are either file share services (used by the client as an extension of their native file systems)
or printable services (used by the client to access print services on the host running the server).
Sections may be designated
guest
services, in which case no password is required to
access them. A specified UNIX
guest account
is used to define access privileges in this
case.
Sections other than guest services will require a password to access them. The client provides the
username. As older clients only provide passwords and not usernames, you may specify a list of usernames to
check against the password using the
user =
option in the share definition. For modern clients
such as Windows 95/98/ME/NT/2000, this should not be necessary.
The access rights granted by the server are masked by the access rights granted to the specified or guest
UNIX user by the host system. The server does not grant more access than the host system grants.
The following sample section defines a file space share. The user has write access to the path
/home/bar
. The share is accessed via the share name
foo
[foo]
path = /home/bar
read only = no
The following sample section defines a printable share. The share is read-only, but printable. That is,
the only write access permitted is via calls to open, write to and close a spool file. The
guest
ok
parameter means access will be permitted as the default guest user (specified elsewhere):
[aprinter]
path = /var/tmp
read only = yes
printable = yes
guest ok = yes
SPECIAL SECTIONS
The [global] section
Parameters in this section apply to the server as a whole, or are defaults for sections that do not
specifically define certain items. See the notes under PARAMETERS for more information.
The [homes] section
If a section called [homes] is included in the configuration file, services connecting clients
to their home directories can be created on the fly by the server.
When the connection request is made, the existing sections are scanned. If a match is found, it is
used. If no match is found, the requested section name is treated as a username and looked up in the local
password file. If the name exists and the correct password has been given, a share is created by cloning the
[homes] section.
Some modifications are then made to the newly created share:
The share name is changed from homes to the located username.
If no path was given, the path is set to the user's home directory.
If you decide to use a
path =
line in your [homes] section, it may be useful
to use the %S macro. For example:
path = /data/pchome/%S
is useful if you have different home directories for your PCs than for UNIX access.
This is a fast and simple way to give a large number of clients access to their home directories with a minimum
of fuss.
A similar process occurs if the requested section name is
homes
, except that the share
name is not changed to that of the requesting user. This method of using the [homes] section works well if
different users share a client PC.
The [homes] section can specify all the parameters a normal service section can specify, though some make more sense
than others. The following is a typical and suitable [homes] section:
[homes]
read only = no
An important point is that if guest access is specified in the [homes] section, all home directories will be
visible to all clients
without a password
. In the very unlikely event that this is actually
desirable, it is wise to also specify
read only access
The
browseable
flag for auto home directories will be inherited from the global browseable
flag, not the [homes] browseable flag. This is useful as it means setting
browseable = no
in
the [homes] section will hide the [homes] share but make any auto home directories visible.
The [printers] section
This section works like [homes], but for printers.
If a [printers] section occurs in the configuration file, users are able to connect to any printer
specified in the local host's printcap file.
When a connection request is made, the existing sections are scanned. If a match is found, it is used.
If no match is found, but a [homes] section exists, it is used as described above. Otherwise, the requested
section name is treated as a printer name and the appropriate printcap file is scanned to see if the requested
section name is a valid printer share name. If a match is found, a new printer share is created by cloning the
[printers] section.
A few modifications are then made to the newly created share:
The share name is set to the located printer name
If no printer name was given, the printer name is set to the located printer name
If the share does not permit guest access and no username was given, the username is set
to the located printer name.
The [printers] service MUST be printable - if you specify otherwise, the server will refuse
to load the configuration file.
Typically the path specified is that of a world-writeable spool directory with the sticky bit set on
it. A typical [printers] entry looks like this:
[printers]
path = /var/tmp
guest ok = yes
printable = yes
All aliases given for a printer in the printcap file are legitimate printer names as far as the server is concerned.
If your printing subsystem doesn't work like that, you will have to set up a pseudo-printcap. This is a file
consisting of one or more lines like this:
alias|alias|alias|alias...
Each alias should be an acceptable printer name for your printing subsystem. In the [global] section,
specify the new file as your printcap. The server will only recognize names found in your pseudo-printcap,
which of course can contain whatever aliases you like. The same technique could be used simply to limit access
to a subset of your local printers.
An alias, by the way, is defined as any component of the first entry of a printcap record. Records are separated by newlines,
components (if there are more than one) are separated by vertical bar symbols (
).
Note
On SYSV systems which use lpstat to determine what printers are defined on the system you may be able to use
printcap name = lpstat
to automatically obtain a list of printers. See the
printcap name
option for more details.
USERSHARES
Starting with Samba version 3.0.23 the capability for non-root users to add, modify, and delete
their own share definitions has been added. This capability is called
usershares
and
is controlled by a set of parameters in the [global] section of the smb.conf.
The relevant parameters are :
usershare allow guests
Controls if usershares can permit guest access.
usershare max shares
Maximum number of user defined shares allowed.
usershare owner only
If set only directories owned by the sharing user can be shared.
usershare path
Points to the directory containing the user defined share definitions.
The filesystem permissions on this directory control who can create user defined shares.
usershare prefix allow list
Comma-separated list of absolute pathnames restricting what directories
can be shared. Only directories below the pathnames in this list are permitted.
usershare prefix deny list
Comma-separated list of absolute pathnames restricting what directories
can be shared. Directories below the pathnames in this list are prohibited.
usershare template share
Names a pre-existing share used as a template for creating new usershares.
All other share parameters not specified in the user defined share definition
are copied from this named share.
To allow members of the UNIX group
foo
to create user defined
shares, create the directory to contain the share definitions as follows:
Become root:
mkdir /usr/local/samba/lib/usershares
chgrp foo /usr/local/samba/lib/usershares
chmod 1770 /usr/local/samba/lib/usershares
Then add the parameters
usershare path = /usr/local/samba/lib/usershares
usershare max shares = 10
# (or the desired number of shares)
to the global
section of your
smb.conf
. Members of the group foo may then manipulate the user defined shares
using the following commands.
net usershare add sharename path [comment] [acl] [guest_ok=[y|n]]
To create or modify (overwrite) a user defined share.
net usershare delete sharename
To delete a user defined share.
net usershare list wildcard-sharename
To list user defined shares.
net usershare info wildcard-sharename
To print information about user defined shares.
PARAMETERS
Parameters define the specific attributes of sections.
Some parameters are specific to the [global] section (e.g.,
security
). Some parameters
are usable in all sections (e.g.,
create mask
). All others are permissible only in normal
sections. For the purposes of the following descriptions the [homes] and [printers] sections will be
considered normal. The letter
in parentheses indicates that a parameter is specific to
the [global] section. The letter
indicates that a parameter can be specified in a
service specific section. All
parameters can also be specified in the [global] section
- in which case they will define the default behavior for all services.
Parameters are arranged here in alphabetical order - this may not create best bedfellows, but at least you can
find them! Where there are synonyms, the preferred synonym is described, others refer to the preferred
synonym.
VARIABLE SUBSTITUTIONS
Many of the strings that are settable in the config file can take substitutions. For example the option
path = /tmp/%u
is interpreted as
path = /tmp/john
if the user connected with the
username john.
These substitutions are mostly noted in the descriptions below, but there are some general substitutions
which apply whenever they might be relevant. These are:
%U
session username (the username that the client wanted, not
necessarily the same as the one they got).
%G
primary group name of %U.
%h
the Internet hostname that Samba is running on.
%m
the NetBIOS name of the client machine (very useful).
This parameter is not available when Samba listens on port 445, as clients no longer
send this information. If you use this macro in an include statement on a domain that has
a Samba domain controller be sure to set in the [global] section
server smb transports =
139
. This will cause Samba to not listen on port 445 and will permit include
functionality to function as it did with Samba 2.x.
%L
the NetBIOS name of the server. This allows you to change your config based on what
the client calls you. Your server can have a
dual personality
%M
the Internet name of the client machine.
%R
the selected protocol level after protocol negotiation. It can be one of
CORE, COREPLUS, LANMAN1, LANMAN2, NT1,
SMB2_02, SMB2_10, SMB3_00, SMB3_02, SMB3_11
or SMB2_FF.
%d
the process id of the current server
process.
%a
The architecture of the remote
machine. It currently recognizes Samba (
Samba
),
the Linux CIFS file system (
CIFSFS
), OS/2, (
OS2
),
Mac OS X (
OSX
), Windows for Workgroups (
WfWg
), Windows 9x/ME
Win95
), Windows NT (
WinNT
),
Windows 2000 (
Win2K
),
Windows XP (
WinXP
),
Windows XP 64-bit(
WinXP64
),
Windows 2003 including
2003R2 (
Win2K3
), and Windows
Vista (
Vista
). Anything else will be known as
UNKNOWN
%I
the IP address of the client machine.
Before 4.0.0 it could contain IPv4 mapped IPv6 addresses,
now it only contains IPv4 or IPv6 addresses.
%J
the IP address of the client machine,
colons/dots replaced by underscores.
%i
the local IP address to which a client connected.
Before 4.0.0 it could contain IPv4 mapped IPv6 addresses,
now it only contains IPv4 or IPv6 addresses.
%j
the local IP address to which a client connected,
colons/dots replaced by underscores.
%T
the current date and time.
%t
the current date and time in a minimal format without colons (YYYYYmmdd_HHMMSS).
%D
name of the domain or workgroup of the current user.
%w
the winbind separator.
%$(
envvar
the value of the environment variable
envar
The following substitutes apply only to some configuration options (only those that are
used when a connection has been established):
%S
the name of the current service, if any.
%P
the root directory of the current service, if any.
%u
username of the current service, if any.
%g
primary group name of %u.
%H
the home directory of the user given by %u.
%N
This value is the same as %L.
There are some quite creative things that can be done with these substitutions and other
smb.conf
options.
NAME MANGLING
Samba supports
name mangling
so that DOS and Windows clients can use files that don't
conform to the 8.3 format. It can also be set to adjust the case of 8.3 format filenames.
There are several options that control the way mangling is performed, and they are grouped here rather
than listed separately. For the defaults look at the output of the testparm program.
These options can be set separately for each service.
The options are:
case sensitive = yes/no/auto
controls whether filenames are case sensitive. If they aren't, Samba must do a filename search and match on
passed names. The default setting of auto allows clients that support case sensitive filenames (Linux CIFSVFS
and smbclient 3.0.5 and above currently) to tell the Samba server on a per-packet basis that they wish to
access the file system in a case-sensitive manner (to support UNIX case sensitive semantics). No Windows or
DOS system supports case-sensitive filename so setting this option to auto is the same as setting it to no
for them. Default
auto
default case = upper/lower
controls what the default case is for new filenames (ie. files that don't currently exist in the filesystem).
Default
lower
. IMPORTANT NOTE: As part of the optimizations for directories containing
large numbers of files, the following special case applies. If the options
case sensitive = yes
preserve case = No
, and
short preserve case = No
are set, then the case of
all
incoming client filenames, not just new filenames, will be modified. See additional notes below.
preserve case = yes/no
controls whether new files (ie. files that don't currently exist in the filesystem) are created with the case
that the client passes, or if they are forced to be the
default
case. Default
yes
short preserve case = yes/no
controls if new files (ie. files that don't currently exist in the filesystem) which conform to 8.3 syntax,
that is all in upper case and of suitable length, are created upper case, or if they are forced to be the
default
case. This option can be used with
preserve case = yes
to permit
long filenames to retain their case, while short names are lowercased. Default
yes
By default, Samba 3.0 has the same semantics as a Windows NT server, in that it is case insensitive
but case preserving. As a special case for directories with large numbers of files, if the case
options are set as follows, "case sensitive = yes", "case preserve = no", "short preserve case = no"
then the "default case" option will be applied and will modify all filenames sent from the client
when accessing this share.
REGISTRY-BASED CONFIGURATION
Starting with Samba version 3.2.0, the capability to
store Samba configuration in the registry is available.
The configuration is stored in the registry key
HKLM\Software\Samba\smbconf
There are two levels of registry configuration:
Share definitions stored in registry are used.
This is triggered by setting the global
parameter
registry shares
to
yes
in
smb.conf
The registry shares are loaded not at startup but
on demand at runtime by
smbd
Shares defined in
smb.conf
take
priority over shares of the same name defined in
registry.
Global
smb.conf
options stored in registry are used. This can be activated
in two different ways:
Firstly, a registry only configuration is triggered
by setting
config backend = registry
in the [global] section of
smb.conf
This resets everything that has been read from config files
to this point and reads the content of the global configuration
section from the registry.
This is the recommended method of using registry based
configuration.
Secondly, a mixed configuration can be activated
by a special new meaning of the parameter
include = registry
in the [global] section of
smb.conf
This reads the global options from registry with the same
priorities as for an include of a text file.
This may be especially useful in cases where an initial
configuration is needed to access the registry.
Activation of global registry options automatically
activates registry shares. So in the registry only case,
shares are loaded on demand only.
Note: To make registry-based configurations foolproof
at least to a certain extent, the use
of
lock directory
and
config backend
inside the registry configuration has been disabled:
Especially by changing the
lock directory
inside the registry
configuration, one would create a broken setup where the daemons
do not see the configuration they loaded once it is active.
The registry configuration can be accessed with
tools like
regedit
or
net (rpc)
registry
in the key
HKLM\Software\Samba\smbconf

More conveniently, the
conf
subcommand of the
net
(8)
utility
offers a dedicated interface to read and write the
registry based configuration locally, i.e. directly
accessing the database file, circumventing the
server.
IDENTITY MAPPING CONSIDERATIONS
In the SMB protocol, users, groups, and machines are represented by their security identifiers (SIDs).
On POSIX system Samba processes need to run under corresponding POSIX user identities and
with supplemental POSIX groups to allow access to the files owned by those users and groups.
The process of mapping SIDs to POSIX users and groups is called
IDENTITY MAPPING
or, in short,
ID MAPPING
Samba supports multiple ways to map SIDs to POSIX users and groups. The configuration is driven by
the
idmap config DOMAIN : OPTION
option which allows one to specify identity
mapping (idmap) options for each domain separately.
Identity mapping modules implement different strategies for mapping of SIDs to POSIX user and group
identities. They are applicable to different use cases and scenarios. It is advised to read the documentation
of the individual identity mapping modules before choosing a specific scenario to use. Each identity
management module is documented in a separate manual page. The standard idmap backends are
tdb (
idmap_tdb
(8)
),
tdb2 (
idmap_tdb2
(8)
),
ldap (
idmap_ldap
(8)
),
rid (
idmap_rid
(8)
),
hash (
idmap_hash
(8)
),
autorid (
idmap_autorid
(8)
),
ad (
idmap_ad
(8)
),
nss (
idmap_nss
(8)
), and
rfc2307 (
idmap_rfc2307
(8)
).
Overall, ID mapping configuration should be decided carefully. Changes to the already deployed ID mapping
configuration may create the risk of losing access to the data or disclosing the data to the wrong parties.
This example shows how to configure two domains with
idmap_rid
(8)
, the principal domain and a trusted domain,
leaving the default id mapping scheme at tdb.
[global]
security = domain
workgroup = MAIN

idmap config * : backend = tdb
idmap config * : range = 1000000-1999999

idmap config MAIN : backend = rid
idmap config MAIN : range = 5000000-5999999

idmap config TRUSTED : backend = rid
idmap config TRUSTED : range = 6000000-6999999
EXPLANATION OF EACH PARAMETER
abort shutdown script (G)
This a full path name to a script called by
smbd
(8)
that
should stop a shutdown procedure issued by the
shutdown script
If the connected user possesses the
SeRemoteShutdownPrivilege
right, this command will be run as root.
Default:
abort shutdown script
""
Example:
abort shutdown script
/sbin/shutdown -c
access based share enum (S)
If this parameter is
yes
for a
service, then the share hosted by the service will only be visible
to users who have read or write access to the share during share
enumeration (for example net view \\sambaserver). The share ACLs
which allow or deny the access to the share can be modified using
for example the
sharesec
command
or using the appropriate Windows tools. This has
parallels to access based enumeration, the main difference being
that only share permissions are evaluated, and security
descriptors on files contained on the share are not used in
computing enumeration access rights.
Default:
access based share enum
no
acl allow execute always (S)
This boolean parameter controls the behaviour of
smbd
(8)
when receiving a protocol request of "open for execution"
from a Windows client.
With Samba 3.6 and older, the execution right in the ACL was not checked, so a client
could execute a file even if it did not have execute rights on the file. In Samba 4.0,
this has been fixed, so that by default, i.e. when this parameter is set to "False",
"open for execution" is now denied when execution permissions are not present.
If this parameter is set to "True", Samba does not check execute permissions on
"open for execution", thus re-establishing the behaviour of Samba 3.6.
This can be useful to smoothen upgrades from older Samba versions to 4.0 and newer.
This setting is not meant to be used as a permanent setting, but as a temporary relief:
It is recommended to fix the permissions in the ACLs and reset this parameter to the
default after a certain transition period.
Default:
acl allow execute always
no
acl check permissions (S)
Please note this parameter is now deprecated in Samba 3.6.2 and will be removed
in a future version of Samba.
This boolean parameter controls what
smbd
(8)
does on receiving a protocol request of "open for delete"
from a Windows client. If a Windows client doesn't have permissions to delete a file then they
expect this to be denied at open time. POSIX systems normally only detect restrictions on delete by
actually attempting to delete the file or directory. As Windows clients can (and do) "back out" a
delete request by unsetting the "delete on close" bit Samba cannot delete the file immediately
on "open for delete" request as we cannot restore such a deleted file. With this parameter set to
true (the default) then smbd checks the file system permissions directly on "open for delete" and denies the
request without actually deleting the file if the file system permissions would seem to deny it.
This is not perfect, as it's possible a user could have deleted a file without Samba being able to
check the permissions correctly, but it is close enough to Windows semantics for mostly correct
behaviour. Samba will correctly check POSIX ACL semantics in this case.
If this parameter is set to "false" Samba doesn't check permissions on "open for delete"
and allows the open. If the user doesn't have permission to delete the file this will only be
discovered at close time, which is too late for the Windows user tools to display an error message
to the user. The symptom of this is files that appear to have been deleted "magically" re-appearing
on a Windows explorer refresh. This is an extremely advanced protocol option which should not
need to be changed. This parameter was introduced in its final form in 3.0.21, an earlier version
with slightly different semantics was introduced in 3.0.20. That older version is not documented here.
Default:
acl check permissions
yes
acl claims evaluation (G)
This option controls the way Samba handles evaluation of
security descriptors in Samba, with regards to Active
Directory Claims. AD Claims, introduced with Windows 2012,
are essentially administrator-defined key-value pairs that can
be set both in Active Directory (communicated via the Kerberos
PAC) and in the security descriptor themselves.
Active Directory claims are new with Samba 4.20.
Because the claims are evaluated against a very flexible
expression language within the security descriptor, this option provides a mechanism
to disable this logic if required by the administrator.
This default behaviour is that claims evaluation is
enabled in the AD DC only. Additionally, claims evaluation on
the AD DC is only enabled if the DC functional level
is 2012 or later. See
ad dc functional level
Possible values are :
AD DC only
: Enabled for the Samba AD
DC (for DC functional level 2012 or higher).
never
: Disabled in all cases.
This option disables some but not all of the
Authentication Policies and Authentication Policy Silos features of
the Windows 2012R2 functional level in the AD DC.
Default:
acl claims evaluation
AD DC only
acl flag inherited canonicalization (S)
This option controls the way Samba handles client requests setting
the Security Descriptor of files and directories and the effect the
operation has on the Security Descriptor flag "DACL
auto-inherited" (DI). Generally, this flag is set on a file (or
directory) upon creation if the parent directory has DI set and also has
inheritable ACEs.
On the other hand when a Security Descriptor is explicitly set on
a file, the DI flag is cleared, unless the flag "DACL Inheritance
Required" (DR) is also set in the new Security Descriptor (fwiw, DR is
never stored on disk).
This is the default behaviour when this option is enabled (the
default). When setting this option to
no
, the
resulting value of the DI flag on-disk is directly taken from the DI
value of the to-be-set Security Descriptor. This can be used so dump
tools like rsync that copy data blobs from xattrs that represent ACLs
created by the acl_xattr VFS module will result in copies of the ACL
that are identical to the source. Without this option, the copied ACLs
would all lose the DI flag if set on the source.
Default:
acl flag inherited canonicalization
yes
acl group control (S)
In a POSIX filesystem, only the owner of a file or directory and the superuser can modify the permissions
and ACLs on a file. If this parameter is set, then Samba overrides this restriction, and also allows the
primary group owner
of a file or directory to modify the permissions and ACLs
on that file.
On a Windows server, groups may be the owner of a file or directory - thus allowing anyone in
that group to modify the permissions on it. This allows the delegation of security controls
on a point in the filesystem to the group owner of a directory and anything below it also owned
by that group. This means there are multiple people with permissions to modify ACLs on a file
or directory, easing manageability.
This parameter allows Samba to also permit delegation of the control over a point in the exported
directory hierarchy in much the same way as Windows. This allows all members of a UNIX group to
control the permissions on a file or directory they have group ownership on.
This parameter is best used with the
inherit owner
option and also
on a share containing directories with the UNIX
setgid bit
set
on them, which causes new files and directories created within it to inherit the group
ownership from the containing directory.
This parameter was deprecated in Samba 3.0.23, but re-activated in
Samba 3.0.31 and above, as it now only controls permission changes if the user
is in the owning primary group. It is now no longer equivalent to the
dos filemode
option.
Default:
acl group control
no
acl map full control (S)
This boolean parameter controls whether
smbd
(8)
maps a POSIX ACE entry of "rwx" (read/write/execute), the maximum
allowed POSIX permission set, into a Windows ACL of "FULL CONTROL". If this parameter is set to true any POSIX
ACE entry of "rwx" will be returned in a Windows ACL as "FULL CONTROL", is this parameter is set to false any
POSIX ACE entry of "rwx" will be returned as the specific Windows ACL bits representing read, write and
execute.
Default:
acl map full control
yes
ad dc functional level (G)
The value of the parameter (a string) is the Active
Directory functional level that this Domain Controller will claim
to support.
Possible values are :
2008_R2
: Similar to Windows
2008 R2 Functional Level
2012
: Similar to Windows
2012 Functional Level
2012_R2
: Similar to Windows
2012 R2 Functional Level
2016
: Similar to Windows
2016 Functional Level
Normally this option should not be set as Samba will operate
per the released functionality of the Samba Active Directory
Domain Controller.
However to access incomplete features in domain functional
level 2016 it may be useful to
set this value, prior to upgrading the domain functional level.
If this is set manually, the protection against mismatching
features between domain controllers is reduced, so all domain
controllers should be running the same version of Samba, to ensure
that behaviour as seen by the client is the same no matter which
DC is contacted.
Setting this to
2016
will allow
raising the domain functional level with
samba-tool
domain level raise --domain-level=2016
and provide
access to Samba's Kerberos Claims and Dynamic Access
Control feature.
Warning
The Samba's Kerberos Claims and Dynamic Access
Control features enabled with
2016
are
incomplete in Samba 4.19.
Default:
ad dc functional level
2008_R2
Example:
ad dc functional level
2016
add group script (G)
This is the full pathname to a script that will be run
AS ROOT
by
smbd
(8)
when a new group is requested. It
will expand any
%g
to the group name passed. This script is only useful
for installations using the Windows NT domain administration tools. The script is free to create a group with
an arbitrary name to circumvent unix group name restrictions. In that case the script must print the numeric
gid of the created group on stdout.
Default:
add group script
Example:
add group script
/usr/sbin/groupadd %g
additional dns hostnames (G)
A list of additional DNS names by which this host can be identified
Default:
additional dns hostnames
# empty string (no additional dns names)
Example:
additional dns hostnames
host2.example.com host3.other.com
add machine script (G)
This is the full pathname to a script that will be run by
smbd
(8)
when a machine is
added to Samba's domain and a Unix account matching the machine's name appended with a "$" does not
already exist.
This option is very similar to the
add user script
, and likewise uses the %u
substitution for the account name. Do not use the %m
substitution.
Default:
add machine script
Example:
add machine script
/usr/sbin/adduser -n -g machines -c Machine -d /var/lib/nobody -s /bin/false %u
addport command (G)
Samba 3.0.23 introduced support for adding printer ports
remotely using the Windows "Add Standard TCP/IP Port Wizard".
This option defines an external program to be executed when
smbd receives a request to add a new Port to the system.
The script is passed two parameters:
port name
device URI
The deviceURI is in the format of socket://[:]
or lpd:///.
Default:
addport command
Example:
addport command
/etc/samba/scripts/addport.sh
addprinter command (G)
With the introduction of MS-RPC based printing
support for Windows NT/2000 clients in Samba 2.2, The MS Add
Printer Wizard (APW) icon is now also available in the
"Printers..." folder displayed a share listing. The APW
allows for printers to be add remotely to a Samba or Windows
NT/2000 print server.
For a Samba host this means that the printer must be
physically added to the underlying printing system.
The
addprinter command
defines a script to be run which
will perform the necessary operations for adding the printer
to the print system and to add the appropriate service definition
to the
smb.conf
file in order that it can be
shared by
smbd
(8)
The
addprinter command
is
automatically invoked with the following parameter (in
order):
printer name
share name
port name
driver name
location
Windows 9x driver location
All parameters are filled in from the PRINTER_INFO_2 structure sent
by the Windows NT/2000 client with one exception. The "Windows 9x
driver location" parameter is included for backwards compatibility
only. The remaining fields in the structure are generated from answers
to the APW questions.
Once the
addprinter command
has
been executed,
smbd
will reparse the
smb.conf
to determine if the share defined by the APW
exists. If the sharename is still invalid, then
smbd
will return an ACCESS_DENIED error to the client.
The
addprinter command
program
can output a single line of text,
which Samba will set as the port the new printer is connected to.
If this line isn't output, Samba won't reload its printer shares.
Default:
addprinter command
Example:
addprinter command
/usr/bin/addprinter
add share command (G)
Samba 2.2.0 introduced the ability to dynamically add and delete shares via the Windows NT 4.0 Server
Manager. The
add share command
is used to define an external program
or script which will add a new service definition to
smb.conf
In order to successfully execute the
add share command
smbd
requires that the administrator
connects using a root account (i.e. uid == 0) or has the
SeDiskOperatorPrivilege
Scripts defined in the
add share command
parameter are executed as root.
When executed,
smbd
will automatically invoke the
add share command
with five parameters.
configFile
- the location of the global
smb.conf
file.
shareName
- the name of the new share.
pathName
- path to an **existing**
directory on disk.
comment
- comment string to associate with the new
share.
max
connections
Number of maximum simultaneous connections to this
share.
This parameter is only used to add file shares. To add printer shares, see the
addprinter command
Default:
add share command
Example:
add share command
/usr/local/bin/addshare
add user script (G)
This is the full pathname to a script that will be run
AS ROOT
by
smbd
(8)
under special circumstances described below.
Normally, a Samba server requires that UNIX users are created for all users accessing
files on this server. For sites that use Windows NT account databases as their primary
user database creating these users and keeping the user list in sync with the Windows
NT PDC is an onerous task. This option allows smbd to create the required UNIX users
ON DEMAND
when a user accesses the Samba server.
When the Windows user attempts to access the Samba server, at login (session setup in
the SMB protocol) time,
smbd
(8)
contacts the
password server
and attempts to authenticate the given user with the given password. If the authentication
succeeds then
smbd
attempts to find a UNIX user in the UNIX
password database to map the Windows user into. If this lookup fails, and
add user script
is set then
smbd
will
call the specified script
AS ROOT
, expanding any
%u
argument to be the user name to create.
If this script successfully creates the user then
smbd
will
continue on as though the UNIX user already existed. In this way, UNIX users are dynamically created to
match existing Windows NT accounts.
See also
security
password server
delete user script
Default:
add user script
Example:
add user script
/usr/local/samba/bin/add_user %u
add user to group script (G)
Full path to the script that will be called when a user is added to a group using the Windows NT domain administration
tools. It will be run by
smbd
(8)
AS ROOT
. Any
%g
will be replaced with the group name and
any
%u
will be replaced with the user name.
Note that the
adduser
command used in the example below does
not support the used syntax on all systems.
Default:
add user to group script
Example:
add user to group script
/usr/sbin/adduser %u %g
administrative share (S)
If this parameter is set to
yes
for
a share, then the share will be an administrative share. The Administrative
Shares are the default network shares created by all Windows NT-based
operating systems. These are shares like C$, D$ or ADMIN$. The type of these
shares is STYPE_DISKTREE_HIDDEN.
See the section below on
security
for more
information about this option.
Default:
administrative share
no
admin users (S)
This is a list of users who will be granted
administrative privileges on the share. This means that they
will do all file operations as the super-user (root).
You should use this option very carefully, as any user in
this list will be able to do anything they like on the share,
irrespective of file permissions.
Default:
admin users
Example:
admin users
jason
afs share (S)
This parameter controls whether special AFS features are enabled
for this share. If enabled, it assumes that the directory exported via
the
path
parameter is a local AFS import. The
special AFS features include the attempt to hand-craft an AFS token
if you enabled --with-fake-kaserver in configure.
Default:
afs share
no
afs token lifetime (G)
This parameter controls the lifetime of tokens that the AFS
fake-kaserver claims. In reality these never expire but this lifetime
controls when the afs client will forget the token.
Set this parameter to 0 to get
NEVERDATE
Default:
afs token lifetime
604800
afs username map (G)
If you are using the fake kaserver AFS feature, you might
want to hand-craft the usernames you are creating tokens for.
For example this is necessary if you have users from several domain
in your AFS Protection Database. One possible scheme to code users
as DOMAIN+User as it is done by winbind with the + as a separator.
The mapped user name must contain the cell name to log into,
so without setting this parameter there will be no token.
Default:
afs username map
Example:
afs username map
%u@afs.samba.org
aio max threads (G)
The integer parameter specifies the maximum number of
threads each smbd process will create when doing parallel asynchronous IO
calls. If the number of outstanding calls is greater than this
number the requests will not be refused but go onto a queue
and will be scheduled in turn as outstanding requests complete.
Related command:
aio read size
Related command:
aio write size
Default:
aio max threads
100
aio read size (S)
If this integer parameter is set to a non-zero value,
Samba will read from files asynchronously when the request size is bigger
than this value. Note that it happens only for non-chained and non-chaining
reads.
The only reasonable values for this parameter are 0 (no async I/O) and
1 (always do async I/O).
Related command:
aio write size
Default:
aio read size
Example:
aio read size
# Always do reads synchronously
aio write behind (S)
If Samba has been built with asynchronous I/O support,
Samba will not wait until write requests are finished before returning
the result to the client for files listed in this parameter.
Instead, Samba will immediately return that the write
request has been finished successfully, no matter if the
operation will succeed or not. This might speed up clients without
aio support, but is really dangerous, because data could be lost
and files could be damaged.
The syntax is identical to the
veto files
parameter.
Default:
aio write behind
Example:
aio write behind
/*.tmp/
aio write size (S)
If this integer parameter is set to a non-zero value,
Samba will write to files asynchronously when the request size is bigger
than this value. Note that it happens only for non-chained and non-chaining
writes.
The only reasonable values for this parameter are 0 (no async I/O) and
1 (always do async I/O).
Compared to
aio read size
this parameter has
a smaller effect, most writes should end up in the
file system cache. Writes that require space allocation might
benefit most from going asynchronous.
Related command:
aio read size
Default:
aio write size
Example:
aio write size
# Always do writes synchronously
algorithmic rid base (G)
This determines how Samba will use its
algorithmic mapping from uids/gid to the RIDs needed to construct
NT Security Identifiers.
Setting this option to a larger value could be useful to sites
transitioning from WinNT and Win2k, as existing user and
group rids would otherwise clash with system users etc.
All UIDs and GIDs must be able to be resolved into SIDs for
the correct operation of ACLs on the server. As such the algorithmic
mapping can't be 'turned off', but pushing it 'out of the way' should
resolve the issues. Users and groups can then be assigned 'low' RIDs
in arbitrary-rid supporting backends.
Default:
algorithmic rid base
1000
Example:
algorithmic rid base
100000
allocation roundup size (S)
This parameter allows an administrator to tune the
allocation size reported to Windows clients. This is only
useful for old SMB1 clients because modern SMB dialects
eliminated that bottleneck and have better performance by
default. Using this parameter may cause
difficulties for some applications, e.g. MS Visual Studio.
If the MS Visual Studio compiler starts to crash with an
internal error, set this parameter to zero for this share.
Settings this parameter to a large value can also cause
small files to allocate more space on the disk than
needed.
This parameter is deprecated and will be removed in
one of the next Samba releases.
The integer parameter specifies the roundup size in bytes.
Default:
allocation roundup size
Example:
allocation roundup size
1048576
# (to set it to the former default of 1 MiB)
allow dcerpc auth level connect (G)
This option controls whether DCERPC services are allowed to
be used with DCERPC_AUTH_LEVEL_CONNECT, which provides authentication,
but no per message integrity nor privacy protection.
Some interfaces like samr, lsarpc and netlogon have a hard-coded default of
no
and epmapper, mgmt and rpcecho have a hard-coded default of
yes
The behavior can be overwritten per interface name (e.g. lsarpc, netlogon, samr, srvsvc,
winreg, wkssvc ...) by using 'allow dcerpc auth level connect:interface = yes' as option.
This option is over-ridden by the implementation specific restrictions.
E.g. the drsuapi and backupkey protocols require DCERPC_AUTH_LEVEL_PRIVACY.
The dnsserver protocol requires DCERPC_AUTH_LEVEL_INTEGRITY.
Default:
allow dcerpc auth level connect
no
Example:
allow dcerpc auth level connect
yes
allow dns updates (G)
This option determines what kind of updates to the DNS are allowed.
DNS updates can either be disallowed completely by setting it to
disabled
, enabled over secure connections only by
setting it to
secure only
or allowed in all cases
by setting it to
nonsecure
Default:
allow dns updates
secure only
Example:
allow dns updates
disabled
allow insecure wide links (G)
In normal operation the option
wide links
which allows the server to follow symlinks outside of a share path
is automatically disabled when
unix extensions
are enabled on a Samba server. This is done for security purposes
to prevent UNIX clients creating symlinks to areas of the server
file system that the administrator does not wish to export.
Setting
allow insecure wide links
to
true disables the link between these two parameters, removing
this protection and allowing a site to configure
the server to follow symlinks (by setting
wide links
to "true") even when
unix extensions
is turned on.
It is not recommended to enable this option unless you
fully understand the implications of allowing the server to
follow symbolic links created by UNIX clients. For most
normal Samba configurations this would be considered a security
hole and setting this parameter is not recommended.
This option was added at the request of sites who had
deliberately set Samba up in this way and needed to continue
supporting this functionality without having to patch the
Samba code.
Default:
allow insecure wide links
no
allow nt4 crypto (G)
This option is deprecated and will be removed in future,
as it is a security problem if not set to "no" (which will be
the hardcoded behavior in future).
This option controls whether the netlogon server (currently
only in 'active directory domain controller' mode), will
reject clients which do not support NETLOGON_NEG_STRONG_KEYS
nor NETLOGON_NEG_SUPPORTS_AES.
This option was added with Samba 4.2.0. It may lock out clients
which worked fine with Samba versions up to 4.1.x. as the effective default
was "yes" there, while it is "no" now.
If you have clients without RequireStrongKey = 1 in the registry,
you may need to set "allow nt4 crypto = yes", until you have fixed all clients.
"allow nt4 crypto = yes" allows weak crypto to be negotiated, maybe via downgrade attacks.
Avoid using this option!
Use explicit '
allow nt4 crypto:COMPUTERACCOUNT = yes
' instead!
Which is available with the patches for
CVE-2022-38023
see
Samba will log an error in the log files at log level 0
if legacy a client is rejected or allowed without an explicit,
allow nt4 crypto:COMPUTERACCOUNT = yes
' option
for the client. The message will indicate
the explicit '
allow nt4 crypto:COMPUTERACCOUNT = yes
line to be added, if the legacy client software requires it. (The log level can be adjusted with
CVE_2022_38023:error_debug_level = 1
in order to complain only at a higher log level).
This allows admins to use "yes" only for a short grace period,
in order to collect the explicit
allow nt4 crypto:COMPUTERACCOUNT = yes
' options.
This option is over-ridden by the effective value of 'yes' from
the '
server reject md5 schannel:COMPUTERACCOUNT
',
reject md5 clients
',
server reject aes schannel:COMPUTERACCOUNT
',
and/or '
server reject aes schannel
' options.
Default:
allow nt4 crypto
no
allow nt4 crypto:COMPUTERACCOUNT (G)
If you still have legacy domain members which required 'allow nt4 crypto = yes',
it is possible to specify an explicit exception per computer account
by using 'allow nt4 crypto:COMPUTERACCOUNT = yes' as option.
Note that COMPUTERACCOUNT has to be the sAMAccountName value of
the computer account (including the trailing '$' sign).
Samba will log a complaint in the log files at log level 0
about the security problem if the option is set to "yes",
but the related computer does not require it.
(The log level can be adjusted with
CVE_2022_38023:warn_about_unused_debug_level = 1
in order to complain only at a higher log level).
Samba will log a warning in the log files at log level 5,
if a setting is still needed for the specified computer account.
See
CVE-2022-38023
This option overrides the
allow nt4 crypto
option.
This option is over-ridden by the effective value of 'yes' from
the '
server reject md5 schannel:COMPUTERACCOUNT
',
reject md5 clients
',
server reject aes schannel:COMPUTERACCOUNT
and/or '
server reject aes schannel
' options.
Which means '
allow nt4 crypto:COMPUTERACCOUNT = yes
is only useful in combination with '
server reject md5 schannel:COMPUTERACCOUNT = no
and '
server reject aes schannel:COMPUTERACCOUNT = no
'.
allow nt4 crypto:LEGACYCOMPUTER1$ = yes
server reject md5 schannel:LEGACYCOMPUTER1$ = no
server reject aes schannel:LEGACYCOMPUTER1$ = no
allow nt4 crypto:NASBOX$ = yes
server reject md5 schannel:NASBOX$ = no
server reject aes schannel:NASBOX$ = no
allow nt4 crypto:LEGACYCOMPUTER2$ = yes
server reject md5 schannel:LEGACYCOMPUTER2$ = no
server reject aes schannel:LEGACYCOMPUTER2$ = no
No default
allow trusted domains (G)
This option only takes effect when the
security
option is set to
server
domain
or
ads
If it is set to no, then attempts to connect to a resource from
a domain or workgroup other than the one which smbd is running
in will fail, even if that domain is trusted by the remote server
doing the authentication.
This is useful if you only want your Samba server to
serve resources to users in the domain it is a member of. As
an example, suppose that there are two domains DOMA and DOMB. DOMB
is trusted by DOMA, which contains the Samba server. Under normal
circumstances, a user with an account in DOMB can then access the
resources of a UNIX account with the same account name on the
Samba server even if they do not have an account in DOMA. This
can make implementing a security boundary difficult.
Default:
allow trusted domains
yes
allow unsafe cluster upgrade (G)
If set to no (the default), smbd checks at startup if
other smbd versions are running in the cluster and refuses to
start if so. This is done to protect data corruption in
internal data structures due to incompatible Samba versions
running concurrently in the same cluster. Setting this
parameter to
yes
disables this
safety check.
Default:
allow unsafe cluster upgrade
no
apply group policies (G)
This option controls whether winbind will execute the gpupdate
command defined in
gpo update command
on the
Group Policy update interval. The Group Policy update interval is
defined as every 90 minutes, plus a random offset between 0 and 30
minutes. This applies Group Policy Machine polices to the client or
KDC and machine policies to a server.
Default:
apply group policies
no
Example:
apply group policies
yes
async dns timeout (G)
The number of seconds the asynchronous DNS
resolver code in Samba will wait for responses.
Some of the Samba client library code uses internal
asynchronous DNS resolution for A and AAAA records
when trying to find Active Directory Domain controllers.
This value prevents this name resolution code from
waiting for DNS server timeouts.
The minimum value of this parameter is clamped
at 1 second.
Default:
async dns timeout
10
Example:
async dns timeout
20
async smb echo handler (G)
This parameter specifies whether Samba should fork the
async smb echo handler. It can be beneficial if your file
system can block syscalls for a very long time. In some
circumstances, it prolongs the timeout that Windows uses to
determine whether a connection is dead. This parameter is only for
SMB1. For SMB2 and above TCP keepalives can be used instead.
Default:
async smb echo handler
no
auth event notification (G)
When enabled, this option causes Samba (acting as an
Active Directory Domain Controller) to stream authentication
events across the internal message bus. Scripts built using
Samba's python bindings can listen to these events by
registering as the service
auth_event
This is
not
needed for the audit
logging described in
log level
Instead, this should instead be considered a developer
option (it assists in the Samba testsuite) rather than a
facility for external auditing, as message delivery is not
guaranteed (a feature that the testsuite works around).
The authentication events are also logged via the normal
logging methods when the
log level
is
set appropriately, say to
auth_json_audit:3
Default:
auth event notification
no
preload
This parameter is a synonym for
auto services
auto services (G)
This is a list of services that you want to be
automatically added to the browse lists. This is most useful
for homes and printers services that would otherwise not be
visible.
Note that if you just want all printers in your
printcap file loaded then the
load printers
option is easier.
Default:
auto services
Example:
auto services
fred lp colorlp
available (S)
This parameter lets you "turn off" a service. If
available = no
, then
ALL
attempts to connect to the service will fail. Such failures are
logged.
Default:
available
yes
bind dns directory
This parameter is a synonym for
binddns dir
binddns dir (G)
This parameters defines the directory samba will use to store the configuration
files for bind, such as named.conf.

NOTE: The bind dns directory needs to be on the same mount point as the private
directory!
Default:
binddns dir
${prefix}/bind-dns
bind interfaces only (G)
This global parameter allows the Samba admin
to limit what interfaces on a machine will serve SMB requests. It
affects file service
smbd
(8)
and name service
nmbd
(8)
in a slightly different ways.
For name service it causes
nmbd
to bind to ports 137 and 138 on the
interfaces listed in the
interfaces
parameter.
nmbd
also binds to the "all addresses" interface (0.0.0.0) on ports 137 and 138 for the purposes of
reading broadcast messages. If this option is not set then
nmbd
will
service name requests on all of these sockets. If
bind interfaces only
is set then
nmbd
will check the source address of any packets coming in on the
broadcast sockets and discard any that don't match the broadcast addresses of the interfaces in the
interfaces
parameter list. As unicast packets are received on the other sockets it
allows
nmbd
to refuse to serve names to machines that send packets that
arrive through any interfaces not listed in the
interfaces
list. IP Source address
spoofing does defeat this simple check, however, so it must not be used seriously as a security feature for
nmbd
For file service it causes
smbd
(8)
to bind only to the interface list given in the
interfaces
parameter. This restricts the networks that
smbd
will
serve, to packets coming in on those interfaces. Note that you should not use this parameter for machines that
are serving PPP or other intermittent or non-broadcast network interfaces as it will not cope with
non-permanent interfaces.
If
bind interfaces only
is set and the network address
127.0.0.1
is not added to the
interfaces
parameter list
smbpasswd
(8)
may not
work as expected due to the reasons covered below.
To change a users SMB password, the
smbpasswd
by default connects to the
localhost - 127.0.0.1
address as an SMB client to issue the password change request. If
bind interfaces only
is set then unless the network address
127.0.0.1
is added to the
interfaces
parameter list then
smbpasswd
will fail to connect in it's default mode.
smbpasswd
can be forced to use the primary IP interface of the local host by using
its
smbpasswd
(8)
-r
remote machine
parameter, with
remote
machine
set to the IP name of the primary interface of the local host.
Default:
bind interfaces only
no
blocking locks (S)
This parameter controls the behavior
of
smbd
(8)
when given a request by a client
to obtain a byte range lock on a region of an open file, and the
request has a time limit associated with it.
If this parameter is set and the lock range requested
cannot be immediately satisfied, samba will internally
queue the lock request, and periodically attempt to obtain
the lock until the timeout period expires.
If this parameter is set to
no
, then
samba will behave as previous versions of Samba would and
will fail the lock request immediately if the lock range
cannot be obtained.
Default:
blocking locks
yes
block size (S)
This parameter controls the behavior of
smbd
(8)
when reporting disk free
sizes. By default, this reports a disk block size of 1024 bytes.
Changing this parameter may have some effect on the
efficiency of client writes, this is not yet confirmed. This
parameter was added to allow advanced administrators to change
it (usually to a higher value) and test the effect it has on
client write performance without re-compiling the code. As this
is an experimental option it may be removed in a future release.
Changing this option does not change the disk free reporting
size, just the block size unit reported to the client.
Default:
block size
1024
Example:
block size
4096
browsable
This parameter is a synonym for
browseable
browseable (S)
This controls whether this share is seen in
the list of available shares in a net view and in the browse list.
Default:
browseable
yes
browse list (G)
This controls whether
smbd
(8)
will serve a browse list to
a client doing a
NetServerEnum
call. Normally
set to
yes
. You should never need to change
this.
Default:
browse list
yes
cache directory (G)
Usually, most of the TDB files are stored in the
lock directory
. Since Samba 3.4.0, it is
possible to differentiate between TDB files with persistent data and
TDB files with non-persistent data using the
state directory
and the
cache directory
options.
This option specifies the directory for storing TDB
files containing non-persistent data that will be kept across
service restarts. The directory should be placed on persistent
storage, but the data can be safely deleted by an
administrator.
Default:
cache directory
${prefix}/var/cache
Example:
cache directory
/var/run/samba/locks/cache
casesignames
This parameter is a synonym for
case sensitive
case sensitive (S)
See the discussion in the section
name mangling
Default:
case sensitive
auto
change notify (G)
This parameter specifies whether Samba should reply
to a client's file change notify requests.
You should never need to change this parameter
Default:
change notify
yes
change share command (G)
Samba 2.2.0 introduced the ability to dynamically add and delete shares via the Windows NT 4.0 Server
Manager. The
change share command
is used to define an external
program or script which will modify an existing service definition in
smb.conf
In order to successfully execute the
change share command
smbd
requires that the administrator
connects using a root account (i.e. uid == 0) or has the
SeDiskOperatorPrivilege
Scripts defined in the
change share command
parameter are executed as root.
When executed,
smbd
will automatically invoke the
change share command
with six parameters.
configFile
- the location
of the global
smb.conf
file.
shareName
- the name of the new
share.
pathName
- path to an **existing**
directory on disk.
comment
- comment string to associate
with the new share.
max
connections
Number of maximum simultaneous connections to this
share.
CSC policy
- client side caching
policy in string form. Valid values are: manual, documents, programs, disable.
This parameter is only used to modify existing file share definitions.
To modify printer shares, use the "Printers..." folder as seen
when browsing the Samba host.
Default:
change share command
Example:
change share command
/usr/local/bin/changeshare
check parent directory delete on close (S)
A Windows SMB server prevents the client from creating files in a
directory that has the delete-on-close flag set. By default Samba doesn't
perform this check as this check is a quite expensive operation in Samba.
Default:
check parent directory delete on close
no
check password script (G)
The name of a program that can be used to check password
complexity. The password is sent to the program's standard input.
The program must return 0 on a good password, or any other value
if the password is bad.
In case the password is considered weak (the program does not return 0) the
user will be notified and the password change will fail.
In Samba AD, this script will be run
AS ROOT
by
samba
(8)
without any substitutions.
Note that starting with Samba 4.11 the following environment variables are exported to the script:
SAMBA_CPS_ACCOUNT_NAME is always present and contains the sAMAccountName of user,
the is the same as the %u substitutions in the none AD DC case.
SAMBA_CPS_USER_PRINCIPAL_NAME is optional in the AD DC case if the userPrincipalName is present.
SAMBA_CPS_FULL_NAME is optional if the displayName is present.
Note: In the example directory is a sample program called
crackcheck
that uses cracklib to check the password quality.
Default:
check password script
# Disabled
Example:
check password script
/usr/local/sbin/crackcheck
client ipc max protocol (G)
The value of the parameter (a string) is the highest
protocol level that will be supported for IPC$ connections as DCERPC transport.
Normally this option should not be set as the automatic
negotiation phase in the SMB protocol takes care of choosing
the appropriate protocol.
The value
default
refers to the latest
supported protocol, currently
SMB3_11
See
client max protocol
for a full list
of available protocols. The values CORE, COREPLUS, LANMAN1, LANMAN2
are silently upgraded to NT1.
Default:
client ipc max protocol
default
Example:
client ipc max protocol
SMB2_10
client ipc min protocol (G)
This setting controls the minimum protocol version that the
will be attempted to use for IPC$ connections as DCERPC transport.
Normally this option should not be set as the automatic
negotiation phase in the SMB protocol takes care of choosing
the appropriate protocol.
The value
default
refers to the higher value
of
NT1
and the effective value of
client min protocol
See
client max protocol
for a full list
of available protocols. The values CORE, COREPLUS, LANMAN1, LANMAN2
are silently upgraded to NT1.
Default:
client ipc min protocol
default
Example:
client ipc min protocol
SMB3_11
client ipc signing (G)
This controls whether the client is allowed or required to use SMB signing for IPC$
connections as DCERPC transport. Possible values
are
desired
required
and
disabled
When set to required or default, SMB signing is mandatory.
When set to desired, SMB signing is offered, but not enforced and if set
to disabled, SMB signing is not offered either.
Connections from winbindd to Active Directory Domain Controllers
always enforce signing.
Default:
client ipc signing
default
client lanman auth (G)
This parameter has been deprecated since Samba 4.13 and
support for LanMan (as distinct from NTLM, NTLMv2 or
Kerberos) authentication as a client
will be removed in a future Samba release.
That is, in the future, the current default of
client NTLMv2 auth = yes
will be the enforced behaviour.
This parameter determines whether or not
smbclient
(8)
and other samba client
tools will attempt to authenticate itself to servers using the
weaker LANMAN password hash. If disabled, only server which support NT
password hashes (e.g. Windows NT/2000, Samba, etc... but not
Windows 95/98) will be able to be connected from the Samba client.
The LANMAN encrypted response is easily broken, due to its
case-insensitive nature, and the choice of algorithm. Clients
without Windows 95/98 servers are advised to disable
this option.
Disabling this option will also disable the
client plaintext auth
option.
Likewise, if the
client ntlmv2
auth
parameter is enabled, then only NTLMv2 logins will be
attempted.
Default:
client lanman auth
no
client ldap sasl wrapping (G)
The
client ldap sasl wrapping
defines whether
ldap traffic will be signed or signed and encrypted (sealed).
Possible values are
plain
sign
and
seal
The values
sign
and
seal
are
only available if Samba has been compiled against a modern
OpenLDAP version (2.3.x or higher).
This option is needed firstly to secure the privacy of
administrative connections from
samba-tool
including in particular new or reset passwords for users. For
this reason the default is
seal
Additionally,
winbindd
and the
net
tool can use LDAP to communicate with
Domain Controllers, so this option also controls the level of
privacy for those connections. All supported AD DC versions
will enforce the usage of at least signed LDAP connections by
default, so a value of at least
sign
is
required in practice.
The default value is
seal
. That implies synchronizing the time
with the KDC in the case of using
Kerberos
In order to force using LDAP (on port 389) with STARTTLS
or LDAPS (on port 636), it is possible to use
starttls
or
ldaps
. In that case the NTLMSSP or Kerberos
authentication using the TLS channel bindings in order to glue
it to the connection.
Default:
client ldap sasl wrapping
seal
client max protocol (G)
The value of the parameter (a string) is the highest
protocol level that will be supported by the client.
Possible values are :
CORE
: Earliest version. No
concept of user names.
COREPLUS
: Slight improvements on
CORE for efficiency.
LANMAN1
: First
modern
version of the protocol. Long filename support.
LANMAN2
: Updates to Lanman1 protocol.
NT1
: Current up to date version of the protocol.
Used by Windows NT. Known as CIFS.
SMB2
: Re-implementation of the SMB protocol.
Used by Windows Vista and later versions of Windows. SMB2 has sub protocols available.
SMB2_02
: The earliest SMB2 version.
SMB2_10
: Windows 7 SMB2 version.
By default SMB2 selects the SMB2_10 variant.
SMB3
: The same as SMB2.
Used by Windows 8. SMB3 has sub protocols available.
SMB3_00
: Windows 8 SMB3 version.
SMB3_02
: Windows 8.1 SMB3 version.
SMB3_11
: Windows 10 SMB3 version.
By default SMB3 selects the SMB3_11 variant.
Normally this option should not be set as the automatic
negotiation phase in the SMB protocol takes care of choosing
the appropriate protocol.
The value
default
refers to
SMB3_11
IPC$ connections for DCERPC e.g. in winbindd, are handled by the
client ipc max protocol
option.
Default:
client max protocol
default
Example:
client max protocol
LANMAN1
client min protocol (G)
This setting controls the minimum protocol version that the
client will attempt to use.
Normally this option should not be set as the automatic
negotiation phase in the SMB protocol takes care of choosing
the appropriate protocol unless you connect to a legacy SMB1-only server.
See
Related command:
client max protocol
for a full list
of available protocols.
IPC$ connections for DCERPC e.g. in winbindd, are handled by the
client ipc min protocol
option.
Note that most command line tools support
--option='client min protocol=NT1', so it may not be required to
enable SMB1 protocols globally in smb.conf.
Default:
client min protocol
SMB2_02
Example:
client min protocol
NT1
client netlogon ping protocol (G)
This option controls the protocol Samba uses to issue netlogon
ping requests. This is normally done via connectionless ldap, but
some installations require LDAPS over TCP port 636 for this.
Possible values are :
CLDAP
LDAP
LDAPS
STARTTLS
Default:
client netlogon ping protocol
CLDAP
client NTLMv2 auth (G)
This parameter has been deprecated since Samba 4.13 and
support for NTLM and LanMan (as distinct from NTLMv2 or
Kerberos authentication)
will be removed in a future Samba release.
That is, in the future, the current default of
client NTLMv2 auth = yes
will be the enforced behaviour.
This parameter determines whether or not
smbclient
(8)
will attempt to
authenticate itself to servers using the NTLMv2 encrypted password
response.
If enabled, only an NTLMv2 and LMv2 response (both much more
secure than earlier versions) will be sent. Older servers
(including NT4 < SP4, Win9x and Samba 2.2) are not compatible with
NTLMv2 when not in an NTLMv2 supporting domain
Similarly, if enabled, NTLMv1,
client lanman auth
and
client plaintext auth
authentication will be disabled. This also disables share-level
authentication.
If disabled, an NTLM response (and possibly a LANMAN response)
will be sent by the client, depending on the value of
client lanman auth
Note that Windows Vista and later versions already use
NTLMv2 by default, and some sites (particularly those following
'best practice' security polices) only allow NTLMv2 responses, and
not the weaker LM or NTLM.
When
client use spnego
is also set to
yes
extended security (SPNEGO) is required
in order to use NTLMv2 only within NTLMSSP. This behavior was
introduced with the patches for CVE-2016-2111.
Default:
client NTLMv2 auth
yes
client plaintext auth (G)
This parameter has been deprecated since Samba 4.13 and
support for plaintext (as distinct from NTLM, NTLMv2 or
Kerberos authentication)
will be removed in a future Samba release.
That is, in the future, the current default of
client plaintext auth = no
will be the enforced behaviour.
Specifies whether a client should send a plaintext
password if the server does not support encrypted passwords.
Default:
client plaintext auth
no
client protection (G)
This parameter defines which protection Samba client
tools should use by default.
Possible client settings are:
default
- Use the individual
default values of the options:
client signing
client smb encrypt
plain
- This will send
everything just as plaintext, signing or
encryption are turned off.
sign
- This will enable
integrity checking.
encrypt
- This will enable
integrity checks and force encryption for
privacy.
Default:
client protection
default
client schannel (G)
This option is deprecated with Samba 4.8 and will be removed in future.
At the same time the default changed to yes, which will be the
hardcoded behavior in future.
This controls whether the client offers or even demands the use of the netlogon schannel.
client schannel = no
does not offer the schannel,
client schannel = auto
offers the schannel but does not
enforce it, and
client schannel = yes
denies access
if the server is not able to speak netlogon schannel.
Note that for active directory domains this is hardcoded to
client schannel = yes
This option is over-ridden by the
require strong key
option.
Default:
client schannel
yes
Example:
client schannel
auto
client signing (G)
This controls whether the client is allowed or required to use SMB signing. Possible values
are
desired
required
and
disabled
When set to desired or default, SMB signing is offered, but not enforced.
When set to required, SMB signing is mandatory and if set
to disabled, SMB signing is not offered either.
IPC$ connections for DCERPC e.g. in winbindd, are handled by the
client ipc signing
option.
Default:
client signing
default
client smb3 encryption algorithms (G)
This parameter specifies the availability and order of
encryption algorithms which are available for negotiation in the SMB3_11 dialect.
It is also possible to remove individual algorithms from the default list,
by prefixing them with '-'. This can avoid having to specify a hardcoded list.
Note: that the removal of AES-128-CCM from the list will result
in SMB3_00 and SMB3_02 being unavailable, as it is the default and only
available algorithm for these dialects.
Default:
client smb3 encryption algorithms
AES-128-GCM, AES-128-CCM, AES-256-GCM, AES-256-CCM
Example:
client smb3 encryption algorithms
AES-256-GCM
Example:
client smb3 encryption algorithms
-AES-128-GCM -AES-128-CCM
client smb encrypt (G)
This parameter controls whether a client should try or is required
to use SMB encryption. It has different effects depending on whether
the connection uses SMB1 or SMB3:
If the connection uses SMB1, then this option controls the use
of a Samba-specific extension to the SMB protocol introduced in
Samba 3.2 that makes use of the Unix extensions.
If the connection uses SMB2 or newer, then this option controls
the use of the SMB-level encryption that is supported in SMB
version 3.0 and above and available in Windows 8 and newer.
This parameter can be set globally. Possible values are
off
if_required
desired
and
required
A special value is
default
which is
the implicit default setting of
if_required
Effects for SMB1
The Samba-specific encryption of SMB1 connections is an
extension to the SMB protocol negotiated as part of the UNIX
extensions. SMB encryption uses the GSSAPI (SSPI on Windows)
ability to encrypt and sign every request/response in a SMB
protocol stream. When enabled it provides a secure method of
SMB/CIFS communication, similar to an ssh protected session, but
using SMB/CIFS authentication to negotiate encryption and
signing keys. Currently this is only supported smbclient of by
Samba 3.2 and newer. Windows does not support this feature.
When set to default, SMB encryption is probed, but not
enforced. When set to required, SMB encryption is required and
if set to disabled, SMB encryption can not be negotiated.
Effects for SMB3 and newer
Native SMB transport encryption is available in SMB version 3.0
or newer. It is only used by Samba if
client max protocol
is set to
SMB3
or newer.
These features can be controlled with settings of
client smb encrypt
as follows:
Leaving it as default, explicitly setting
default
, or setting it to
if_required
globally will enable
negotiation of encryption but will not turn on
data encryption globally.
Setting it to
desired
globally
will enable negotiation and will turn on data encryption
on sessions and share connections for those servers
that support it.
Setting it to
required
globally
will enable negotiation and turn on data encryption
on sessions and share connections. Clients that do
not support encryption will be denied access to the
server.
Setting it to
off
globally will
completely disable the encryption feature for all
connections.
Default:
client smb encrypt
default
client smb3 signing algorithms (G)
This parameter specifies the availability and order of
signing algorithms which are available for negotiation in the SMB3_11 dialect.
It is also possible to remove individual algorithms from the default list,
by prefixing them with '-'. This can avoid having to specify a hardcoded list.
Note: that the removal of AES-128-CMAC from the list will result
in SMB3_00 and SMB3_02 being unavailable, and the removal of HMAC-SHA256
will result in SMB2_02 and SMB2_10 being unavailable, as these are the default and only
available algorithms for these dialects.
Default:
client smb3 signing algorithms
AES-128-GMAC, AES-128-CMAC, HMAC-SHA256
Example:
client smb3 signing algorithms
AES-128-CMAC, HMAC-SHA256
Example:
client smb3 signing algorithms
-AES-128-CMAC
client smb transports (G)
Specifies which transports and ports the client should try to connect to for SMB traffic.
The order matters as they are tried in order with short delays for the fallbacks.
The transport 'tcp' uses raw tcp with a 4 byte length header per SMB PDU.
The default port for 'tcp' is 445. Other ports can be specified by adding it
after ':', e.g. 'tcp:1445'.
The transport 'nbt' uses netbios framing on top of tcp per SMB PDU.
The default port for 'nbt' is 139. Other ports can be specified by adding it
after ':', e.g. 'nbt:1139'.
The transport 'quic' uses the quic protocol on top of udp.
The default port for 'quic' is 443. Other ports can be specified by adding it
after ':', e.g. 'quic:1443'.
The following options are also relevant:
tls enabled
tls ca directories
tls trust system cas
tls cafile
tls certfile
tls keyfile
and
tls verify peer
Note: 'quic' requires the quic.ko kernel module for Linux from
Linux versions may support it natively.
Numerical ports are handled as 'tcp' except port '139' is handled as 'nbt'.
Note that's currently a limit of 10 unique transports, all others will
be ignored.
Default:
client smb transports
tcp, nbt
Example:
client smb transports
445
Example:
client smb transports
tcp, tcp:1445
Example:
client smb transports
8000, nbt:1139
Example:
client smb transports
tcp, quic, nbt
Example:
client smb transports
+quic
client use kerberos (G)
This parameter determines whether Samba client tools will try
to authenticate using Kerberos. For Kerberos authentication you
need to use dns names instead of IP addresses when connecting
to a service.
Possible option settings are:
desired
- Kerberos
authentication will be tried first and if it fails it
automatically fallback to NTLM.
required
- Kerberos
authentication will be required. There will be no
fallback to NTLM or a different alternative.
off
- Don't use
Kerberos, use NTLM instead or another
alternative.
In case that weak cryptography is not allowed (e.g. FIPS mode)
the default will be forced to
required
Default:
client use kerberos
desired
client use krb5 netlogon (G)
This option is experimental for now!
This option controls whether winbindd (and other client tools)
try to use ServerAuthenticateKerberos for the netlogon secure channel.
The behavior can be controlled per netbios domain
by using 'client use krb5 netlogon:NETBIOSDOMAIN = yes|no' as option.
This option is over-ridden by the
reject aes netlogon servers
option (if it is effectively on)
and lets
client use krb5 netlogon
be yes as well.
The 'default' currently maps to 'no'.
A meaning of 'auto' depends on the used kerberos library
and the trust/domain type.
If samba was compiled using '--without-ads' or
'--with-system-heimdalkrb5' it is not possible to
activate the ServerAuthenticateKerberos feature,
as the krb5_init_creds_step() function is not available.
This forces 'auto' to behave as 'no'.
The value of 'auto' maps to 'yes' if the domain
is detected as active directory domain, e.g.
with 'SECURITY = ADS' or on an active directory domain controller.
WARNING: This option is experimental in this Samba version
(see VERSION section below) and should not be used in production!
Default:
client use krb5 netlogon
default
Example:
client use krb5 netlogon
no
Example:
client use krb5 netlogon
auto
Example:
client use krb5 netlogon
yes
client use spnego (G)
This parameter has been deprecated since Samba 4.13 and
support for NTLMv2, NTLM and LanMan authentication outside NTLMSSP
will be removed in a future Samba release.
That is, in the future, the current default of
client use spnego = yes
will be the enforced behaviour.
This variable controls whether Samba clients will try
to use Simple and Protected NEGOtiation (as specified by rfc2478) with
supporting servers (including WindowsXP, Windows2000 and Samba
3.0) to agree upon an authentication
mechanism. This enables Kerberos authentication in particular.
When
client NTLMv2 auth
is also set to
yes
extended security (SPNEGO) is required
in order to use NTLMv2 only within NTLMSSP. This behavior was
introduced with the patches for CVE-2016-2111.
Default:
client use spnego
yes
cluster addresses (G)
With this parameter you can add additional addresses that
nmbd will register with a WINS server. Similarly, these
addresses will be registered by default when
net ads dns register
is called with
clustering = yes
configured.
Default:
cluster addresses
Example:
cluster addresses
10.0.0.1 10.0.0.2 10.0.0.3
clustering (G)
This parameter specifies whether Samba should contact
ctdb for accessing its tdb files and use ctdb as a backend
for its messaging backend.
Set this parameter to
yes
only if
you have a cluster setup with ctdb running.
Default:
clustering
no
comment (S)
This is a text field that is seen next to a share
when a client does a queries the server, either via the network
neighborhood or via
net view
to list what shares
are available.
If you want to set the string that is displayed next to the
machine name then see the
server string
parameter.
Default:
comment
# No comment
Example:
comment
Fred's Files
config backend (G)
This controls the backend for storing the configuration.
Possible values are
file
(the default)
and
registry
When
config backend = registry
is encountered while loading
smb.conf
the configuration read so far is dropped and the global
options are read from registry instead. So this triggers a
registry only configuration. Share definitions are not read
immediately but instead
registry
shares
is set to
yes
Note: This option can not be set inside the registry
configuration itself.
Default:
config backend
file
Example:
config backend
registry
config file (G)
This allows you to override the config file
to use, instead of the default (usually
smb.conf
).
There is a chicken and egg problem here as this option is set
in the config file!
For this reason, if the name of the config file has changed
when the parameters are loaded then it will reload them from
the new config file.
This option takes the usual substitutions, which can
be very useful.
If the config file doesn't exist then it won't be loaded
(allowing you to special case the config files of just a few
clients).
No default
Example:
config file
/usr/local/samba/lib/smb.conf.%m
copy (S)
This parameter allows you to "clone" service
entries. The specified service is simply duplicated under the
current service's name. Any parameters specified in the current
section will override those in the section being copied.
This feature lets you set up a 'template' service and
create similar services easily. Note that the service being
copied must occur earlier in the configuration file than the
service doing the copying.
Default:
copy
Example:
copy
otherservice
create krb5 conf (G)
Setting this parameter to
no
prevents
winbind from creating custom krb5.conf files. Winbind normally does
this because the krb5 libraries are not AD-site-aware and thus would
pick any domain controller out of potentially very many. Winbind
is site-aware and makes the krb5 libraries use a local DC by
creating its own krb5.conf files.
Preventing winbind from doing this might become necessary if you
have to add special options into your system-krb5.conf that winbind
does not see.
Default:
create krb5 conf
yes
create mode
This parameter is a synonym for
create mask
create mask (S)
When a file is created, the necessary permissions are calculated according to the mapping from DOS modes to
UNIX permissions, and the resulting UNIX mode is then bit-wise 'AND'ed with this parameter. This parameter may
be thought of as a bit-wise MASK for the UNIX modes of a file. Any bit
not
set here will
be removed from the modes set on a file when it is created.
The default value of this parameter removes the
group
and
other
write and execute bits from the UNIX modes.
Following this Samba will bit-wise 'OR' the UNIX mode created from this parameter with the value of the
force create mode
parameter which is set to 000 by default.
This parameter does not affect directory masks. See the parameter
directory mask
for details.
Default:
create mask
0744
Example:
create mask
0775
csc policy (S)
This stands for
client-side caching policy
, and specifies how clients capable of offline
caching will cache the files in the share. The valid values are: manual, documents, programs, disable.
These values correspond to those used on Windows servers.
For example, shares containing roaming profiles can have offline caching disabled using
csc policy = disable
Default:
csc policy
manual
Example:
csc policy
programs
ctdbd socket (G)
If you set
clustering=yes
you need to tell Samba where ctdbd listens on its unix domain
socket. The default path as of ctdb 1.0 is /tmp/ctdb.socket which
you have to explicitly set for Samba in smb.conf.
Default:
ctdbd socket
Example:
ctdbd socket
/tmp/ctdb.socket
ctdb locktime warn threshold (G)
In a cluster environment using Samba and ctdb it is critical
that locks on central ctdb-hosted databases like locking.tdb
are not held for long. With the current Samba architecture
it happens that Samba takes a lock and while holding that
lock makes file system calls into the shared cluster file
system. This option makes Samba warn if it detects that it
has held locks for the specified number of milliseconds. If
this happens,
smbd
will emit a debug level 0
message into its logs and potentially into syslog. The most likely
reason for such a log message is that an operation of the cluster
file system Samba exports is taking longer than expected.
The messages are meant as a debugging aid for potential
cluster problems.
The default value of 0 disables this logging.
Default:
ctdb locktime warn threshold
ctdb timeout (G)
This parameter specifies a timeout in milliseconds for the
connection between Samba and ctdb. It is only valid if you
have compiled Samba with clustering and if you have
set
clustering=yes
When something in the cluster blocks, it can happen that
we wait indefinitely long for ctdb, just adding to the
blocking condition. In a well-running cluster this should
never happen, but there are too many components in a cluster
that might have hickups. Choosing the right balance for this
value is very tricky, because on a busy cluster long service
times to transfer something across the cluster might be
valid. Setting it too short will degrade the service your
cluster presents, setting it too long might make the cluster
itself not recover from something severely broken for too
long.
Be aware that if you set this parameter, this needs to be in
the file smb.conf, it is not really helpful to put this into
a registry configuration (typical on a cluster), because to
access the registry contact to ctdb is required.
Setting
ctdb timeout
to n makes
any process waiting longer than n milliseconds for a reply by the
cluster panic. Setting it to 0 (the default) makes Samba
block forever, which is the highly recommended default.
Default:
ctdb timeout
cups connection timeout (G)
This parameter is only applicable if
printing
is set to
cups
If set, this option specifies the number of seconds that smbd will wait
whilst trying to contact to the CUPS server. The connection will fail
if it takes longer than this number of seconds.
Default:
cups connection timeout
30
Example:
cups connection timeout
60
cups encrypt (G)
This parameter is only applicable if
printing
is set to
cups
and if you use CUPS newer than
1.0.x.It is used to define whether or not Samba should use encryption
when talking to the CUPS server. Possible values are
auto
yes
and
no
When set to auto we will try to do a TLS handshake on each CUPS
connection setup. If that fails, we will fall back to unencrypted
operation.
Default:
cups encrypt
no
cups options (S)
This parameter is only applicable if
printing
is
set to
cups
. Its value is a free form string of options
passed directly to the cups library.
You can pass any generic print option known to CUPS (as listed
in the CUPS "Software Users' Manual"). You can also pass any printer
specific option (as listed in "lpoptions -d printername -l")
valid for the target queue.
Multiple parameters should be space-delimited name/value pairs according to
the PAPI text option ABNF specification. Collection values
("name={a=... b=... c=...}") are stored with the curley brackets intact.
You should set this parameter to
raw
if your CUPS server
error_log
file contains messages such as
"Unsupported format 'application/octet-stream'" when printing from a Windows client
through Samba. It is no longer necessary to enable
system wide raw printing in
/etc/cups/mime.{convs,types}
Default:
cups options
""
Example:
cups options
"raw media=a4"
cups server (G)
This parameter is only applicable if
printing
is set to
cups
If set, this option overrides the ServerName option in the CUPS
client.conf
. This is
necessary if you have virtual samba servers that connect to different CUPS daemons.
Optionally, a port can be specified by separating the server name
and port number with a colon. If no port was specified,
the default port for IPP (631) will be used.
Default:
cups server
""
Example:
cups server
mycupsserver
Example:
cups server
mycupsserver:1631
dcerpc endpoint servers (G)
Specifies which DCE/RPC endpoint servers should be run.
Default:
dcerpc endpoint servers
epmapper, wkssvc, samr, netlogon, lsarpc, drsuapi, dssetup, unixinfo, browser, eventlog6, backupkey, dnsserver
Example:
dcerpc endpoint servers
rpcecho
deadtime (G)
The value of the parameter (a decimal integer)
represents the number of minutes of inactivity before a connection
is considered dead, and it is disconnected. The deadtime only takes
effect if the number of open files is zero.
This is useful to stop a server's resources being
exhausted by a large number of inactive connections.
Most clients have an auto-reconnect feature when a
connection is broken so in most cases this parameter should be
transparent to users.
Using this parameter with a timeout of a few minutes
is recommended for most systems.
A deadtime of zero indicates that no auto-disconnection
should be performed.
Default:
deadtime
10080
Example:
deadtime
15
debug class (G)
With this boolean parameter enabled, the debug class (DBGC_CLASS)
will be displayed in the debug header.
For more information about currently available debug classes, see
section about
log level
Default:
debug class
no
debug encryption (G)
This option will make the smbd server and client code using
libsmb (smbclient, smbget, smbspool, ...) dump the Session Id,
the decrypted Session Key, the Signing Key, the Application Key,
the Encryption Key and the Decryption Key every time an SMB3+
session is established. This information will be printed in logs
at level 0.
Warning: access to these values enables the decryption of any
encrypted traffic on the dumped sessions. This option should
only be enabled for debugging purposes.
Default:
debug encryption
no
debug hires timestamp (G)
Sometimes the timestamps in the log messages are needed with a resolution of higher that seconds, this
boolean parameter adds microsecond resolution to the timestamp message header when turned on.
Note that the parameter
debug timestamp
or
debug syslog format
must be on for this to have an effect.
Default:
debug hires timestamp
yes
debug pid (G)
When using only one log file for more then one forked
smbd
(8)
-process there may be hard to follow which process outputs which
message. This boolean parameter is adds the process-id to the timestamp message headers in the
logfile when turned on.
Note that the parameter
debug timestamp
must be on for this to have an effect.
Default:
debug pid
no
debug prefix timestamp (G)
With this option enabled, the timestamp message header is prefixed to the debug message without the
filename and function information that is included with the
debug timestamp
parameter. This gives timestamps to the messages without adding an additional line.
Note that this parameter overrides the
debug timestamp
parameter.
Default:
debug prefix timestamp
no
debug syslog format (G)
With this option enabled (
yes
(alias
in_logs
) or
always
), debug messages are printed in a
single-line format like that traditionally produced by syslog.
The timestamp consists of an abbreviated month, space-padded date,
and time including seconds. This is followed by the hostname and
the program name, with the process-ID in square brackets.
The value
always
produces this log
format even to
STDOUT
or
STDERR
The value
no
defers to other parameters
and typically produces traditional two-line Samba logs to log files.
If
debug hires timestamp
is also enabled
then an RFC5424 timestamp is used instead.
Default:
debug syslog format
no
winbind debug traceid (G)
With this boolean parameter enabled, the per request unique traceid
will be displayed in the debug header for winbind processes.
Default:
winbind debug traceid
yes
debug uid (G)
Samba is sometimes run as root and sometime run as the connected user, this boolean parameter inserts the
current euid, egid, uid and gid to the timestamp message headers in the log file if turned on.
Note that the parameter
debug timestamp
must be on for this to have an effect.
Default:
debug uid
no
dedicated keytab file (G)
Specifies the absolute path to the kerberos keytab file when
kerberos method
is set to "dedicated
keytab".
Default:
dedicated keytab file
Example:
dedicated keytab file
/usr/local/etc/krb5.keytab
default case (S)
See the section on
name mangling
Also note the
short preserve case
parameter.
Default:
default case
lower
default devmode (S)
This parameter is only applicable to
printable
services.
When smbd is serving Printer Drivers to Windows NT/2k/XP clients, each printer on the Samba
server has a Device Mode which defines things such as paper size and
orientation and duplex settings. The device mode can only correctly be
generated by the printer driver itself (which can only be executed on a
Win32 platform). Because smbd is unable to execute the driver code
to generate the device mode, the default behavior is to set this field
to NULL.
Most problems with serving printer drivers to Windows NT/2k/XP clients
can be traced to a problem with the generated device mode. Certain drivers
will do things such as crashing the client's Explorer.exe with a NULL devmode.
However, other printer drivers can cause the client's spooler service
(spoolsv.exe) to die if the devmode was not created by the driver itself
(i.e. smbd generates a default devmode).
This parameter should be used with care and tested with the printer
driver in question. It is better to leave the device mode to NULL
and let the Windows client set the correct values. Because drivers do not
do this all the time, setting
default devmode = yes
will instruct smbd to generate a default one.
For more information on Windows NT/2k printing and Device Modes,
see the
MSDN documentation
Default:
default devmode
yes
default
This parameter is a synonym for
default service
default service (G)
This parameter specifies the name of a service
which will be connected to if the service actually requested cannot
be found. Note that the square brackets are
NOT
given in the parameter value (see example below).
There is no default value for this parameter. If this
parameter is not given, attempting to connect to a nonexistent
service results in an error.
Typically the default service would be a
guest ok
read only
service.
Also note that the apparent service name will be changed to equal
that of the requested service, this is very useful as it allows you to use macros like
%S
to make a wildcard service.
Note also that any "_" characters in the name of the service
used in the default service will get mapped to a "/". This allows for
interesting things.
Default:
default service
Example:
default service
pub
defer sharing violations (G)
Windows allows specifying how a file will be shared with
other processes when it is opened. Sharing violations occur when
a file is opened by a different process using options that violate
the share settings specified by other processes. This parameter causes
smbd to act as a Windows server does, and defer returning a "sharing
violation" error message for up to one second, allowing the client
to close the file causing the violation in the meantime.
UNIX by default does not have this behaviour.
There should be no reason to turn off this parameter, as it is
designed to enable Samba to more correctly emulate Windows.
Default:
defer sharing violations
yes
delete group script (G)
This is the full pathname to a script that will
be run
AS ROOT
by
smbd
(8)
when a group is requested to be deleted.
It will expand any
%g
to the group name passed.
This script is only useful for installations using the Windows NT domain administration tools.
Default:
delete group script
deleteprinter command (G)
With the introduction of MS-RPC based printer
support for Windows NT/2000 clients in Samba 2.2, it is now
possible to delete a printer at run time by issuing the
DeletePrinter() RPC call.
For a Samba host this means that the printer must be
physically deleted from the underlying printing system. The
deleteprinter command
defines a script to be run which
will perform the necessary operations for removing the printer
from the print system and from
smb.conf
The
deleteprinter command
is
automatically called with only one parameter:
printer name
Once the
deleteprinter command
has
been executed,
smbd
will reparse the
smb.conf
to check that the associated printer no longer exists.
If the sharename is still valid, then
smbd
will return an ACCESS_DENIED error to the client.
Default:
deleteprinter command
Example:
deleteprinter command
/usr/bin/removeprinter
delete readonly (S)
This parameter allows readonly files to be deleted.
This is not normal DOS semantics, but is allowed by UNIX.
This option may be useful for running applications such
as rcs, where UNIX file ownership prevents changing file
permissions, and DOS semantics prevent deletion of a read only file.
Default:
delete readonly
no
delete share command (G)
Samba 2.2.0 introduced the ability to dynamically add and delete shares via the Windows NT 4.0 Server
Manager. The
delete share command
is used to define an external
program or script which will remove an existing service definition from
smb.conf
In order to successfully execute the
delete share command
smbd
requires that the administrator
connects using a root account (i.e. uid == 0) or has the
SeDiskOperatorPrivilege
Scripts defined in the
delete share command
parameter are executed as root.
When executed,
smbd
will automatically invoke the
delete share command
with two parameters.
configFile
- the location
of the global
smb.conf
file.
shareName
- the name of
the existing service.
This parameter is only used to remove file shares. To delete printer shares,
see the
deleteprinter command
Default:
delete share command
Example:
delete share command
/usr/local/bin/delshare
delete user from group script (G)
Full path to the script that will be called when
a user is removed from a group using the Windows NT domain administration
tools. It will be run by
smbd
(8)
AS ROOT
Any
%g
will be replaced with the group name and
any
%u
will be replaced with the user name.
Default:
delete user from group script
Example:
delete user from group script
/usr/sbin/deluser %u %g
delete user script (G)
This is the full pathname to a script that will
be run by
smbd
(8)
when managing users
with remote RPC (NT) tools.
This script is called when a remote client removes a user
from the server, normally using 'User Manager for Domains' or
rpcclient
This script should delete the given UNIX username.
Default:
delete user script
Example:
delete user script
/usr/local/samba/bin/del_user %u
delete veto files (S)
This option is used when Samba is attempting to
delete a directory that contains one or more vetoed files
or directories or non-visible files or directories (such
as dangling symlinks that point nowhere).
(see the
veto files
hide special files
hide unreadable
hide unwriteable files
options). If this option is set to
no
(the default) then if a vetoed
directory contains any non-vetoed files or directories then the
directory delete will fail. This is usually what you want.
If this option is set to
yes
, then Samba
will attempt to recursively delete any files and directories within
the vetoed directory. This can be useful for integration with file
serving systems such as NetAtalk which create meta-files within
directories you might normally veto DOS/Windows users from seeing
(e.g.
.AppleDouble
Setting
delete veto files = yes
allows these
directories to be transparently deleted when the parent directory
is deleted (so long as the user has permissions to do so).
Default:
delete veto files
no
dfree cache time (S)
The
dfree cache time
should only be used on systems where a problem
occurs with the internal disk space calculations. This has been known to happen with Ultrix, but may occur
with other operating systems. The symptom that was seen was an error of "Abort Retry Ignore" at the
end of each directory listing.
This is a new parameter introduced in Samba version 3.0.21. It specifies in seconds the time that smbd will
cache the output of a disk free query. If set to zero (the default) no caching is done. This allows a heavily
loaded server to prevent rapid spawning of
dfree command
scripts increasing the load.
By default this parameter is zero, meaning no caching will be done.
No default
Example:
dfree cache time
60
dfree command (S)
The
dfree command
setting should only be used on systems where a
problem occurs with the internal disk space calculations. This has been known to happen with Ultrix, but may
occur with other operating systems. The symptom that was seen was an error of "Abort Retry Ignore"
at the end of each directory listing.
This setting allows the replacement of the internal routines to calculate the total disk space and amount
available with an external routine. The example below gives a possible script that might fulfill this
function.
In Samba version 3.0.21 this parameter has been changed to be a per-share parameter, and in addition the
parameter
dfree cache time
was added to allow the output of this script to be cached
for systems under heavy load.
The external program will be passed a single parameter indicating a directory in the filesystem being queried.
This will typically consist of the string
./
. The script should return
two integers in ASCII. The first should be the total disk space in blocks, and the second should be the number
of available blocks. An optional third return value can give the block size in bytes. The default blocksize is
1024 bytes.
Note: Your script should
NOT
be setuid or setgid and should be owned by (and writeable
only by) root!
Where the script dfree (which must be made executable) could be:
#!/bin/sh
df "$1" | tail -1 | awk '{print $(NF-4),$(NF-2)}'
or perhaps (on Sys V based systems):
#!/bin/sh
/usr/bin/df -k "$1" | tail -1 | awk '{print $3" "$5}'
Note that you may have to replace the command names with full path names on some systems.
Also note the arguments passed into the script should be quoted inside the script in case they
contain special characters such as spaces or newlines.
By default internal routines for determining the disk capacity and remaining space will be used.
No default
Example:
dfree command
/usr/local/samba/bin/dfree
dgram port (G)
Specifies which ports the server should listen on for NetBIOS datagram traffic.
Default:
dgram port
138
directory mode
This parameter is a synonym for
directory mask
directory mask (S)
This parameter is the octal modes which are
used when converting DOS modes to UNIX modes when creating UNIX
directories.
When a directory is created, the necessary permissions are
calculated according to the mapping from DOS modes to UNIX permissions,
and the resulting UNIX mode is then bit-wise 'AND'ed with this
parameter. This parameter may be thought of as a bit-wise MASK for
the UNIX modes of a directory. Any bit
not
set
here will be removed from the modes set on a directory when it is
created.
The default value of this parameter removes the 'group'
and 'other' write bits from the UNIX mode, allowing only the
user who owns the directory to modify it.
Following this Samba will bit-wise 'OR' the UNIX mode
created from this parameter with the value of the
force directory mode
parameter.
This parameter is set to 000 by default (i.e. no extra mode bits are added).
Default:
directory mask
0755
Example:
directory mask
0775
directory security mask (S)
This parameter has been removed for Samba 4.0.0.
No default
disable netbios (G)
Enabling this parameter will disable netbios support
in Samba. Netbios is the only available form of browsing in
Windows versions prior to Windows 2000.
Note
Clients that only support netbios won't be able to
see your samba server when netbios support is disabled.
Default:
disable netbios
no
disable spoolss (G)
Enabling this parameter will disable Samba's support
for the SPOOLSS set of MS-RPC's and will yield identical behavior
as Samba 2.0.x. Windows NT/2000 clients will downgrade to using
Lanman style printing commands. Windows 9x/ME will be unaffected by
the parameter. However, this will also disable the ability to upload
printer drivers to a Samba server via the Windows NT Add Printer
Wizard or by using the NT printer properties dialog window. It will
also disable the capability of Windows NT/2000 clients to download
print drivers from the Samba host upon demand.
Be very careful about enabling this parameter.
Default:
disable spoolss
no
dmapi support (S)
This parameter specifies whether Samba should use DMAPI to
determine whether a file is offline or not. This would typically
be used in conjunction with a hierarchical storage system that
automatically migrates files to tape.
Note that Samba infers the status of a file by examining the
events that a DMAPI application has registered interest in. This
heuristic is satisfactory for a number of hierarchical storage
systems, but there may be system for which it will fail. In this
case, Samba may erroneously report files to be offline.
This parameter is only available if a supported DMAPI
implementation was found at compilation time. It will only be used
if DMAPI is found to enabled on the system at run time.
Default:
dmapi support
no
dns hostname (G)
This value is used:
to register DNS record with AD during a join or by calling
net ads dns register
during Kerberos authentication to create service principal names
during keytab creation - see the
sync machine password to keytab
parameter
This is not supported in samba-tool yet.
Default:
dns hostname
[netbios name].[realm]
Example:
dns hostname
client-hostname.example.com
dns forwarder (G)
This option specifies the list of DNS servers that DNS requests will be
forwarded to if they can not be handled by Samba itself.
The DNS forwarder is only used if the internal DNS server
in Samba is used. Port numbers can be appended by separating them from
the address by using a colon (':'). When specifying a port, IPv6
addresses must be enclosed in square brackets ('[' and ']'). IPv6
forwarder addresses with no port specified, don't need the square
brackets, and default to port 53.
Default:
dns forwarder
Example:
dns forwarder
192.168.0.1 192.168.0.2 ::1 [2001:db8::1] [2001:db8:1:2::1]:54
dns port (G)
Specifies which ports the server should listen on for
DNS traffic.
It makes possible to use another DNS server as a front
and forward to Samba.
Warning
Dynamic DNS updates may not be proxied by the front
DNS server when forwarding to Samba. Dynamic DNS update
proxying depends on the features of the other DNS server
used as a front.
Default:
dns port
53
dns proxy (G)
Specifies that
nmbd
(8)
when acting as a WINS server and
finding that a NetBIOS name has not been registered, should treat the
NetBIOS name word-for-word as a DNS name and do a lookup with the DNS server
for that name on behalf of the name-querying client.
Note that the maximum length for a NetBIOS name is 15
characters, so the DNS name (or DNS alias) can likewise only be
15 characters, maximum.
nmbd
spawns a second copy of itself to do the
DNS name lookup requests, as doing a name lookup is a blocking
action.
Default:
dns proxy
yes
dns update command (G)
This option sets the command that is called when there are
DNS updates. It should update the local machines DNS names using
TSIG-GSS.
Default:
dns update command
${prefix}/sbin/samba_dnsupdate
Example:
dns update command
/usr/local/sbin/dnsupdate
dns zone scavenging (G)
When enabled (the default is disabled) unused dynamic dns records are
periodically removed.
Warning
This option should not be enabled for installations created with
versions of samba before 4.9. Doing this will result in the loss of
static DNS entries. This is due to a bug in previous versions
of samba (BUG 12451) which marked dynamic DNS records as static and
static records as dynamic.
Note
If one record for a DNS name is static (non-aging) then no other record
for that DNS name will be scavenged.
Default:
dns zone scavenging
no
dns zone transfer clients allow (G)
This option specifies the list of IPs authorized to ask for dns zone
transfer from bind DLZ module.
The IP list is comma and space separated and specified in the same
syntax as used in
hosts allow
, specifically
including IP address, IP prefixes and IP address masks.
As this is a DNS server option, hostnames are naturally not permitted.
The default behaviour is to deny any request.
A request will be authorized only if the emitting client is identified
in this list, and not in
dns zone transfer clients deny
Default:
dns zone transfer clients allow
Example:
dns zone transfer clients allow
192.168.0.1
dns zone transfer clients deny (G)
This option specifies the list of IPs denied to ask for dns zone
transfer from bind DLZ module.
The IP list is comma and space separated and specified in the same
syntax as used in
hosts allow
, specifically
including IP address, IP prefixes and IP address masks.
As this is a DNS server option, hostnames are naturally not permitted.
If a client identified in this list sends a zone transfer request, it will always
be denied, even if they are in
dns zone transfer clients allow
This allows the definition of specific denied clients within an authorized subnet.
Default:
dns zone transfer clients deny
Example:
dns zone transfer clients deny
192.168.0.1
domain logons (G)
This parameter has been deprecated since Samba 4.13 and
support for NT4-style domain logons(as distinct from the Samba
AD DC) will be removed in a future Samba release.
That is, in the future, the current default of
domain logons = no
will be the enforced behaviour.
If set to
yes
, the Samba server will
provide the netlogon service for Windows 9X network logons for the
workgroup
it is in.
This will also cause the Samba server to act as a domain
controller for NT4 style domain services. For more details on
setting up this feature see the Domain Control chapter of the
Samba HOWTO Collection.
Default:
domain logons
no
domain master (G)
Tell
smbd
(8)
to enable
WAN-wide browse list collation. Setting this option causes
nmbd
to claim a
special domain specific NetBIOS name that identifies it as a domain master browser for its given
workgroup
. Local master browsers in the same
workgroup
on
broadcast-isolated subnets will give this
nmbd
their local browse lists,
and then ask
smbd
(8)
for a
complete copy of the browse list for the whole wide area network. Browser clients will then contact their
local master browser, and will receive the domain-wide browse list, instead of just the list for their
broadcast-isolated subnet.
Note that Windows NT Primary Domain Controllers expect to be able to claim this
workgroup
specific special NetBIOS name that identifies them as domain master browsers for that
workgroup
by default (i.e. there is no way to prevent a Windows NT PDC from attempting
to do this). This means that if this parameter is set and
nmbd
claims the
special name for a
workgroup
before a Windows NT PDC is able to do so then cross
subnet browsing will behave strangely and may fail.
If
domain logons = yes
, then the default behavior is to enable the
domain master
parameter. If
domain logons
is not enabled (the
default setting), then neither will
domain master
be enabled by default.
When
domain logons = Yes
the default setting for this parameter is
Yes, with the result that Samba will be a PDC. If
domain master = No
Samba will function as a BDC. In general, this parameter should be set to 'No' only on a BDC.
Default:
domain master
auto
dont descend (S)
There are certain directories on some systems
(e.g., the
/proc
tree under Linux) that are either not
of interest to clients or are infinitely deep (recursive). This
parameter allows you to specify a comma-delimited list of directories
that the server should always show as empty.
Note that Samba can be very fussy about the exact format
of the "dont descend" entries. For example you may need
./proc
instead of just
/proc
Experimentation is the best policy :-)
Default:
dont descend
Example:
dont descend
/proc,/dev
dos charset (G)
DOS SMB clients assume the server has
the same charset as they do. This option specifies which
charset Samba should use to talk to DOS clients.
The default depends on which charsets you have installed.
Samba tries to use charset 850 but falls back to ASCII in
case it is not available. Run
testparm
(1)
to check the default on your system.
No default
dos filemode (S)
The default behavior in Samba is to provide
UNIX-like behavior where only the owner of a file/directory is
able to change the permissions on it. However, this behavior
is often confusing to DOS/Windows users. Enabling this parameter
allows a user who has write access to the file (by whatever
means, including an ACL permission) to modify the permissions
(including ACL) on it. Note that a user belonging to the group
owning the file will not be allowed to change permissions if
the group is only granted read access. Ownership of the
file/directory may also be changed.

Note that using the VFS modules acl_xattr or acl_tdb which store native
Windows as meta-data will automatically turn this option on for any
share for which they are loaded, as they require this option to emulate
Windows ACLs correctly.
Default:
dos filemode
no
dos filetime resolution (S)
Under the DOS and Windows FAT filesystem, the finest
granularity on time resolution is two seconds. Setting this parameter
for a share causes Samba to round the reported time down to the
nearest two second boundary when a query call that requires one second
resolution is made to
smbd
(8)
This option is mainly used as a compatibility option for Visual
C++ when used against Samba shares. If oplocks are enabled on a
share, Visual C++ uses two different time reading calls to check if a
file has changed since it was last read. One of these calls uses a
one-second granularity, the other uses a two second granularity. As
the two second call rounds any odd second down, then if the file has a
timestamp of an odd number of seconds then the two timestamps will not
match and Visual C++ will keep reporting the file has changed. Setting
this option causes the two timestamps to match, and Visual C++ is
happy.
Default:
dos filetime resolution
no
dos filetimes (S)
Under DOS and Windows, if a user can write to a
file they can change the timestamp on it. Under POSIX semantics,
only the owner of the file or root may change the timestamp. By
default, Samba emulates the DOS semantics and allows one to change the
timestamp on a file if the user
smbd
is acting
on behalf has write permissions.
Due to changes in Microsoft Office 2000 and beyond,
the default for this parameter has been changed from "no" to "yes" in Samba 3.0.14
and above. Microsoft Excel will display dialog box warnings about the file being
changed by another user if this parameter is not set to "yes" and files are being
shared between users.
Default:
dos filetimes
yes
dsdb event notification (G)
When enabled, this option causes Samba (acting as an
Active Directory Domain Controller) to stream Samba database
events across the internal message bus. Scripts built using
Samba's python bindings can listen to these events by
registering as the service
dsdb_event
This is
not
needed for the audit
logging described in
log level
Instead, this should instead be considered a developer
option (it assists in the Samba testsuite) rather than a
facility for external auditing, as message delivery is not
guaranteed (a feature that the testsuite works around).
The Samba database events are also logged via the normal
logging methods when the
log level
is
set appropriately, say to
dsdb_json_audit:5
Default:
dsdb event notification
no
dsdb group change notification (G)
When enabled, this option causes Samba (acting as an
Active Directory Domain Controller) to stream group membership change
events across the internal message bus. Scripts built using
Samba's python bindings can listen to these events by
registering as the service
dsdb_group_event
This is
not
needed for the audit
logging described in
log level
Instead, this should instead be considered a developer
option (it assists in the Samba testsuite) rather than a
facility for external auditing, as message delivery is not
guaranteed (a feature that the testsuite works around).
The Samba database events are also logged via the normal
logging methods when the
log level
is
set appropriately, say to
dsdb_group_json_audit:5
Default:
dsdb group change notification
no
dsdb password event notification (G)
When enabled, this option causes Samba (acting as an
Active Directory Domain Controller) to stream password change
and reset events across the internal message bus.
Scripts built using Samba's python bindings can listen to these
events by registering as the service
password_event
This is
not
needed for the audit
logging described in
log level
Instead, this should instead be considered a developer
option (it assists in the Samba testsuite) rather than a
facility for external auditing, as message delivery is not
guaranteed (a feature that the testsuite works around).
The Samba database events are also logged via the normal
logging methods when the
log level
is
set appropriately, say to
dsdb_password_json_audit:5
Default:
dsdb password event notification
no
durable handles (S)
This boolean parameter controls
whether Samba can grant SMB2 durable file handles on a share.
Note that durable handles are only enabled if
kernel oplocks = no
kernel share modes = no
, and
posix locking = no
i.e. if the share is configured for CIFS/SMB2 only access,
not supporting interoperability features with local UNIX processes
or NFS operations.
Also note that, for the time being, durability is not granted
for a handle that has the delete on close flag set.
Default:
durable handles
yes
ea support (S)
This boolean parameter controls whether
smbd
(8)
will allow clients to attempt to access extended
attributes on a share. In order to enable this parameter on a setup with default VFS modules:
Samba must have been built with extended attributes support.
The underlying filesystem exposed by the share must support extended
attributes (e.g. the getfattr(1) / setfattr(1)
utilities must work).
Access to extended user attributes must be allowed by the underlying
filesystem (e.g. when mounted with a system-dependent option like user_xattr on Linux).
This option exposes the "user" attribute namespace from the underlying filesystem to
clients. In order to match Windows conventions, the namespace prefix ("user.") is
stripped from the attribute name on the client side. The handling of further attribute
namespaces (like "security", "system", or "trusted") is not affected by this option.
Note that the SMB protocol allows setting attributes whose value is 64K bytes long,
and that on NTFS, the maximum storage space for extended attributes per file is 64K.
On some filesystem the limits may be lower. Filesystems with too limited EA
space may experience unexpected weird effects.

The default has changed to yes in Samba release 4.9.0 and above to allow better Windows
fileserver compatibility in a default install.
Default:
ea support
yes
elasticsearch:address (S)
Specifies the name of the Elasticsearch server to use for Spotlight
queries when using the Elasticsearch backend.
Default:
elasticsearch:address
localhost
Example:
elasticsearch:address
needle.haystack.samba.org
elasticsearch:force substring search (G)
Force string searches in string attributes likes paths to be prefix
searches by prefixing a *. Example: a Spotlight search for '*=="samba*"'
would be mapped to "'query': '(*samba*)'" instead of "'query':
'(samba*)'".
Default:
elasticsearch:force substring search
no
Example:
elasticsearch:force substring search
yes
elasticsearch:ignore unknown attribute (G)
Ignore unknown Spotlight attributes in search queries. An example query
using the unsupported attribute
"kMDItemTopic"
would be
kMDItemTopic=="hotstuff"
. By
default any query using such a type would completely fail. By enabling
this option, if the type match is a subexpression of a larger expression,
then this subexpression is just ignored.
Default:
elasticsearch:ignore unknown attribute
no
Example:
elasticsearch:ignore unknown attribute
yes
elasticsearch:ignore unknown type (G)
Ignore unknown Spotlight types in search queries. An example query using
the unsupported type
"public.calendar-event"
would be
kMDItemContentType=="public.calendar-event"
. By
default any query using such a type would completely fail. By enabling
this option, if the type match is a subexpression of a larger expression,
then this subexpression is just ignored.
Default:
elasticsearch:ignore unknown type
no
Example:
elasticsearch:ignore unknown type
yes
elasticsearch:index (S)
Specifies the name of the Elasticsearch index to use for Spotlight queries
when using the Elasticsearch backend. The default value of "_all" is a
special Elasticsearch value that performs the search operation on all
indices.
Default:
elasticsearch:index
_all
Example:
elasticsearch:index
spotlight
elasticsearch:mappings (G)
Path to a file specifying metadata attribute mappings in JSON format. Use
by the Elasticsearch backend of the Spotlight RPC service.
Default:
elasticsearch:mappings
${prefix}/var/samba/elasticsearch_mappings.json
Example:
elasticsearch:mappings
/usr/share/foo/mymappings.json
elasticsearch:max results (S)
Path to a file specifying metadata attribute mappings in JSON format. Used
by the Elasticsearch backend of the Spotlight RPC service. A value of 0
means no limit.
Default:
elasticsearch:max results
100
Example:
elasticsearch:max results
10
elasticsearch:port (S)
Specifies the TCP port of the Elasticsearch server to use for Spotlight
queries when using the Elasticsearch backend.
Default:
elasticsearch:port
9200
Example:
elasticsearch:port
9201
elasticsearch:use tls (S)
Specifies whether to use HTTPS when talking to the Elasticsearch server
used for Spotlight queries when using the Elasticsearch backend.
Default:
elasticsearch:use tls
no
Example:
elasticsearch:use tls
yes
enable asu support (G)
Hosts running the "Advanced Server for Unix (ASU)" product
require some special accommodations such as creating a builtin [ADMIN$]
share that only supports IPC connections. The has been the default
behavior in smbd for many years. However, certain Microsoft applications
such as the Print Migrator tool require that the remote server support
an [ADMIN$] file share. Disabling this parameter allows for creating
an [ADMIN$] file share in smb.conf.
Default:
enable asu support
no
enable core files (G)
This parameter specifies whether core dumps should be written
on internal exits. Normally set to
yes
You should never need to change this.
Default:
enable core files
yes
Example:
enable core files
no
enable privileges (G)
This deprecated parameter controls whether or not smbd will honor privileges assigned to specific SIDs via either
net rpc rights
or one of the Windows user and group manager tools. This parameter is
enabled by default. It can be disabled to prevent members of the Domain Admins group from being able to
assign privileges to users or groups which can then result in certain smbd operations running as root that
would normally run under the context of the connected user.
An example of how privileges can be used is to assign the right to join clients to a Samba controlled
domain without providing root access to the server via smbd.
Please read the extended description provided in the Samba HOWTO documentation.
Default:
enable privileges
yes
enable spoolss (G)
Inverted synonym for
disable spoolss
Default:
enable spoolss
yes
encrypt passwords (G)
This parameter has been deprecated since Samba 4.11 and
support for plaintext (as distinct from NTLM, NTLMv2
or Kerberos authentication)
will be removed in a future Samba release.
That is, in the future, the current default of
encrypt passwords = yes
will be the enforced behaviour.
This boolean controls whether encrypted passwords
will be negotiated with the client. Note that Windows NT 4.0 SP3 and
above and also Windows 98 will by default expect encrypted passwords
unless a registry entry is changed. To use encrypted passwords in
Samba see the chapter "User Database" in the Samba HOWTO Collection.
MS Windows clients that expect Microsoft encrypted passwords and that
do not have plain text password support enabled will be able to
connect only to a Samba server that has encrypted password support
enabled and for which the user accounts have a valid encrypted password.
Refer to the smbpasswd command man page for information regarding the
creation of encrypted passwords for user accounts.
The use of plain text passwords is NOT advised as support for this feature
is no longer maintained in Microsoft Windows products. If you want to use
plain text passwords you must set this parameter to no.
In order for encrypted passwords to work correctly
smbd
(8)
must either
have access to a local
smbpasswd
(5)
file (see the
smbpasswd
(8)
program for information on how to set up
and maintain this file), or set the
security = [domain|ads]
parameter which
causes
smbd
to authenticate against another
server.
Default:
encrypt passwords
yes
enhanced browsing (G)
This option enables a couple of enhancements to
cross-subnet browse propagation that have been added in Samba
but which are not standard in Microsoft implementations.
The first enhancement to browse propagation consists of a regular
wildcard query to a Samba WINS server for all Domain Master Browsers,
followed by a browse synchronization with each of the returned
DMBs. The second enhancement consists of a regular randomised browse
synchronization with all currently known DMBs.
You may wish to disable this option if you have a problem with empty
workgroups not disappearing from browse lists. Due to the restrictions
of the browse protocols, these enhancements can cause a empty workgroup
to stay around forever which can be annoying.
In general you should leave this option enabled as it makes
cross-subnet browse propagation much more reliable.
Default:
enhanced browsing
yes
enumports command (G)
The concept of a "port" is fairly foreign
to UNIX hosts. Under Windows NT/2000 print servers, a port
is associated with a port monitor and generally takes the form of
a local port (i.e. LPT1:, COM1:, FILE:) or a remote port
(i.e. LPD Port Monitor, etc...). By default, Samba has only one
port defined--
"Samba Printer Port"
. Under
Windows NT/2000, all printers must have a valid port name.
If you wish to have a list of ports displayed (
smbd
does not use a port name for anything) other than
the default
"Samba Printer Port"
, you
can define
enumports command
to point to
a program which should generate a list of ports, one per line,
to standard output. This listing will then be used in response
to the level 1 and 2 EnumPorts() RPC.
Default:
enumports command
Example:
enumports command
/usr/bin/listports
eventlog list (G)
This option defines a list of log names that Samba will
report to the Microsoft EventViewer utility. The listed
eventlogs will be associated with tdb file on disk in the
$(statedir)/eventlog
The administrator must use an external process to parse the normal
Unix logs such as
/var/log/messages
and write then entries to the eventlog tdb files. Refer to the
eventlogadm(8) utility for how to write eventlog entries.
Default:
eventlog list
Example:
eventlog list
Security Application Syslog Apache
fake directory create times (S)
NTFS and Windows VFAT file systems keep a create
time for all files and directories. This is not the same as the
ctime - status change time - that Unix keeps, so Samba by default
reports the earliest of the various times Unix does keep. Setting
this parameter for a share causes Samba to always report midnight
1-1-1980 as the create time for directories.
This option is mainly used as a compatibility option for
Visual C++ when used against Samba shares. Visual C++ generated
makefiles have the object directory as a dependency for each object
file, and a make rule to create the directory. Also, when NMAKE
compares timestamps it uses the creation time when examining a
directory. Thus the object directory will be created if it does not
exist, but once it does exist it will always have an earlier
timestamp than the object files it contains.
However, Unix time semantics mean that the create time
reported by Samba will be updated whenever a file is created
or deleted in the directory. NMAKE finds all object files in
the object directory. The timestamp of the last one built is then
compared to the timestamp of the object directory. If the
directory's timestamp if newer, then all object files
will be rebuilt. Enabling this option
ensures directories always predate their contents and an NMAKE build
will proceed as expected.
Default:
fake directory create times
no
fake oplocks (S)
Oplocks are the way that SMB clients get permission
from a server to locally cache file operations. If a server grants
an oplock (opportunistic lock) then the client is free to assume
that it is the only one accessing the file and it will aggressively
cache file data. With some oplock types the client may even cache
file open/close operations. This can give enormous performance benefits.
When you set
fake oplocks = yes
smbd
(8)
will
always grant oplock requests no matter how many clients are using the file.
It is generally much better to use the real
oplocks
support rather
than this parameter.
If you enable this option on all read-only shares or
shares that you know will only be accessed from one client at a
time such as physically read-only media like CDROMs, you will see
a big performance improvement on many operations. If you enable
this option on shares where multiple clients may be accessing the
files read-write at the same time you can get data corruption. Use
this option carefully!
Default:
fake oplocks
no
follow symlinks (S)
This parameter allows the Samba administrator to stop
smbd
(8)
from following symbolic links in a particular share. Setting this
parameter to
no
prevents any file or directory that is a symbolic link from being
followed (the user will get an error). This option is very useful to stop users from adding a symbolic
link to
/etc/passwd
in their home directory for instance. However
it will slow filename lookups down slightly.
This option is enabled (i.e.
smbd
will follow symbolic links) by default.
Default:
follow symlinks
yes
force create mode (S)
This parameter specifies a set of UNIX mode bit
permissions that will
always
be set on a
file created by Samba. This is done by bitwise 'OR'ing these bits onto
the mode bits of a file that is being created. The default for this parameter is (in octal)
000. The modes in this parameter are bitwise 'OR'ed onto the file
mode after the mask set in the
create mask
parameter is applied.
The example below would force all newly created files to have read and execute
permissions set for 'group' and 'other' as well as the
read/write/execute bits set for the 'user'.
Default:
force create mode
0000
Example:
force create mode
0755
force directory mode (S)
This parameter specifies a set of UNIX mode bit
permissions that will
always
be set on a directory
created by Samba. This is done by bitwise 'OR'ing these bits onto the
mode bits of a directory that is being created. The default for this
parameter is (in octal) 0000 which will not add any extra permission
bits to a created directory. This operation is done after the mode
mask in the parameter
directory mask
is
applied.
The example below would force all created directories to have read and execute
permissions set for 'group' and 'other' as well as the
read/write/execute bits set for the 'user'.
Default:
force directory mode
0000
Example:
force directory mode
0755
force directory security mode (S)
This parameter has been removed for Samba 4.0.0.
No default
group
This parameter is a synonym for
force group
force group (S)
This specifies a UNIX group name that will be
assigned as the default primary group for all users connecting
to this service. This is useful for sharing files by ensuring
that all access to files on service will use the named group for
their permissions checking. Thus, by assigning permissions for this
group to the files and directories within this service the Samba
administrator can restrict or allow sharing of these files.
In Samba 2.0.5 and above this parameter has extended
functionality in the following way. If the group name listed here
has a '+' character prepended to it then the current user accessing
the share only has the primary group default assigned to this group
if they are already assigned as a member of that group. This allows
an administrator to decide that only users who are already in a
particular group will create files with group ownership set to that
group. This gives a finer granularity of ownership assignment. For
example, the setting
force group = +sys
means
that only users who are already in group sys will have their default
primary group assigned to sys when accessing this Samba share. All
other users will retain their ordinary primary group.
If the
force user
parameter is also set the group specified in
force group
will override the primary group
set in
force user
Default:
force group
Example:
force group
agroup
force printername (S)
When printing from Windows NT (or later),
each printer in
smb.conf
has two
associated names which can be used by the client. The first
is the sharename (or shortname) defined in smb.conf. This
is the only printername available for use by Windows 9x clients.
The second name associated with a printer can be seen when
browsing to the "Printers" (or "Printers and Faxes") folder
on the Samba server. This is referred to simply as the printername
(not to be confused with the
printer name
option).
When assigning a new driver to a printer on a remote
Windows compatible print server such as Samba, the Windows client
will rename the printer to match the driver name just uploaded.
This can result in confusion for users when multiple
printers are bound to the same driver. To prevent Samba from
allowing the printer's printername to differ from the sharename
defined in smb.conf, set
force printername = yes
Be aware that enabling this parameter may affect migrating
printers from a Windows server to Samba since Windows has no way to
force the sharename and printername to match.
It is recommended that this parameter's value not be changed
once the printer is in use by clients as this could cause a user
not be able to delete printer connections from their local Printers
folder.
Default:
force printername
no
smbd force process locks (S)
This boolean option tells
smbd
whether
to forcefully disable the use of Open File Description locks on Linux.
This option should not be changed from the default unless you know what
you're doing.
Default:
smbd force process locks
no
force security mode (S)
This parameter has been removed for Samba 4.0.0.
No default
force unknown acl user (S)
If this parameter is set, a Windows NT ACL that contains an unknown SID (security descriptor, or
representation of a user or group id) as the owner or group owner of the file will be silently
mapped into the current UNIX uid or gid of the currently connected user.
This is designed to allow Windows NT clients to copy files and folders containing ACLs that were
created locally on the client machine and contain users local to that machine only (no domain
users) to be copied to a Samba server (usually with XCOPY /O) and have the unknown userid and
groupid of the file owner map to the current connected user. This can only be fixed correctly
when winbindd allows arbitrary mapping from any Windows NT SID to a UNIX uid or gid.
Try using this parameter when XCOPY /O gives an ACCESS_DENIED error.
Default:
force unknown acl user
no
force user (S)
This specifies a UNIX user name that will be
assigned as the default user for all users connecting to this service.
This is useful for sharing files. You should also use it carefully
as using it incorrectly can cause security problems.
This user name only gets used once a connection is established.
Thus clients still need to connect as a valid user and supply a
valid password. Once connected, all file operations will be performed
as the "forced user", no matter what username the client connected
as. This can be very useful.
In Samba 2.0.5 and above this parameter also causes the
primary group of the forced user to be used as the primary group
for all file activity. Prior to 2.0.5 the primary group was left
as the primary group of the connecting user (this was a bug).
Default:
force user
Example:
force user
auser
fss: prune stale (G)
When enabled, Samba's File Server Remote VSS Protocol (FSRVP) server
checks all FSRVP initiated snapshots on startup, and removes any
corresponding state (including share definitions) for nonexistent
snapshot paths.
Default:
fss: prune stale
no
Example:
fss: prune stale
yes
fss: sequence timeout (G)
The File Server Remote VSS Protocol (FSRVP) server includes a message
sequence timer to ensure cleanup on unexpected client disconnect. This
parameter overrides the default timeout between FSRVP operations.
FSRVP timeouts can be completely disabled via a value of 0.
Default:
fss: sequence timeout
180 or 1800, depending on operation
Example:
fss: sequence timeout
fstype (S)
This parameter allows the administrator to configure the string that specifies the type of filesystem a share
is using that is reported by
smbd
(8)
when a client queries the filesystem type for a share. The default type is
NTFS
for compatibility
with Windows NT but this can be changed to other strings such as
Samba
or
FAT
if required.
Default:
fstype
NTFS
Example:
fstype
Samba
get quota command (G)
The
get quota command
should only be used
whenever there is no operating system API available from the OS that
samba can use.
This option is only available Samba was compiled with
quotas support.
This parameter should specify the path to a script that
queries the quota information for the specified
user/group for the partition that
the specified directory is on.
Such a script is being given 3 arguments:
directory
type of query
uid of user or gid of group
The directory is actually mostly just "." - It needs to be
treated relatively to the current working directory that the script can
also query.
The type of query can be one of:
1 - user quotas
2 - user default quotas (uid = -1)
3 - group quotas
4 - group default quotas (gid = -1)
This script should print one line as output with spaces between the columns. The printed columns should be:
1 - quota flags (0 = no quotas, 1 = quotas enabled, 2 = quotas enabled and enforced)
2 - number of currently used blocks
3 - the softlimit number of blocks
4 - the hardlimit number of blocks
5 - currently used number of inodes
6 - the softlimit number of inodes
7 - the hardlimit number of inodes
8 (optional) - the number of bytes in a block(default is 1024)
Default:
get quota command
Example:
get quota command
/usr/local/sbin/query_quota
getwd cache (G)
This is a tuning option. When this is enabled a
caching algorithm will be used to reduce the time taken for getwd()
calls. This can have a significant impact on performance, especially
when the
wide links
parameter is set to
no
Default:
getwd cache
yes
gpo update command (G)
This option sets the command that is called to apply GPO policies.
The samba-gpupdate script applies System Access and Kerberos Policies
to the KDC. System Access policies set minPwdAge, maxPwdAge,
minPwdLength, and pwdProperties in the samdb. Kerberos Policies set
kdc:service ticket lifetime, kdc:user ticket lifetime, and kdc:renewal
lifetime in smb.conf.
Default:
gpo update command
${prefix}/sbin/samba-gpupdate
Example:
gpo update command
/usr/local/sbin/gpoupdate
guest account (G)
This is a username which will be used for access
to services which are specified as
guest ok
(see below). Whatever privileges this
user has will be available to any client connecting to the guest service.
This user must exist in the password file, but does not require
a valid login. The user account "ftp" is often a good choice
for this parameter.
On some systems the default guest account "nobody" may not
be able to print. Use another account in this case. You should test
this by trying to log in as your guest user (perhaps by using the
su -
command) and trying to print using the
system print command such as
lpr(1)
or
lp(1)
This parameter does not accept % macros, because
many parts of the system require this value to be
constant for correct operation.
Default:
guest account
nobody
# default can be changed at compile-time
Example:
guest account
ftp
public
This parameter is a synonym for
guest ok
guest ok (S)
If this parameter is
yes
for
a service, then no password is required to connect to the service.
Privileges will be those of the
guest account
This parameter nullifies the benefits of setting
restrict anonymous = 2
See the section below on
security
for more information about this option.
Default:
guest ok
no
only guest
This parameter is a synonym for
guest only
guest only (S)
If this parameter is
yes
for
a service, then only guest connections to the service are permitted.
This parameter will have no effect if
guest ok
is not set for the service.
See the section below on
security
for more information about this option.
Default:
guest only
no
hide dot files (S)
This is a boolean parameter that controls whether
files starting with a dot appear as hidden files.
Default:
hide dot files
yes
hide files (S)
This is a list of files or directories that are not
visible but are accessible. The DOS 'hidden' attribute is applied
to any files or directories that match.
Each entry in the list must be separated by a '/',
which allows spaces to be included in the entry. '*'
and '?' can be used to specify multiple files or directories
as in DOS wildcards.
hide files
can also be used as a
parametric option where NAME in
hide files : NAME =
specifies a user or group name with the same syntax as
valid users
. This parametric form can
be specified multiple times for different users or
groups. This means that "hide files : NAME" set both
in the [global] and the share section add up, whereas normally
options set in a share section overwrite the default in the
[global] section.
Each entry must be a Unix path, not a DOS path and must
not include the Unix directory separator '/'.
Note that the case sensitivity option is applicable
in hiding files.
Setting this parameter will affect the performance of Samba,
as it will be forced to check all files and directories for a match
as they are scanned.
The example shown above is based on files that the Macintosh
SMB client (DAVE) available from
Thursby
creates for internal use, and also still hides
all files beginning with a dot.
An example of us of this parameter is:
hide files = /.*/DesktopFolderDB/TrashFor%m/resource.frk/

; Hide some files for anyone and some files for specific users and groups
hide files = /hideforall1/
hide files : USER = /hidetoforuser/
hide files : GROUP = /hideforgroup/
hide files : UNIVERSITY\Alumnis = /somefile.txt/
hide files : john@university.org = /anotherfile.txt/
hide files : S-1-5-21-123-456-789-1000 = /secretfile.txt/
Default:
hide files
# no file are hidden
hide new files timeout (S)
Setting this parameter to something but 0 hides files
that have been modified less than N seconds ago.
It can be used for ingest/process queue style workloads. A
processing application should only see files that are definitely
finished. As many applications do not have proper external workflow
control, this can be a way to make sure processing does not
interfere with file ingest.
Default:
hide new files timeout
hide special files (S)
This parameter prevents clients from seeing special files such as sockets, devices and
fifo's in directory listings.
Default:
hide special files
no
hide unreadable (S)
This parameter prevents clients from seeing the
existence of files that cannot be read. Defaults to off.
Please note that enabling this can slow down listing large
directories significantly. Samba has to evaluate the ACLs of all
directory members, which can be a lot of effort.
Default:
hide unreadable
no
hide unwriteable files (S)
This parameter prevents clients from seeing the existence of files that cannot be written to.
Defaults to off. Note that unwriteable directories are shown as usual.
Please note that enabling this can slow down listing large
directories significantly. Samba has to evaluate the ACLs of all directory
members, which can be a lot of effort.
Default:
hide unwriteable files
no
himmelblaud hello enabled (G)
This parameter controls Hello enrollment and authentication to
Azure Entra ID. By default, it is disabled to prevent security risks,
such as on hosts exposing the SSH port. Administrators should enable
this setting only when Hello enrollment is appropriate for their
environment.
Default:
himmelblaud hello enabled
no
Example:
himmelblaud hello enabled
yes
himmelblaud hsm pin path (G)
Specifies the file path where the HSM PIN is stored. This PIN is used
for unlocking TPM objects required for Azure Entra ID authentication. The HSM
PIN is critical for ensuring secure communication and authentication within
the Himmelblaud daemon.
Default:
himmelblaud hsm pin path
${prefix}/var/lib/himmelblaud/hsm-pin
himmelblaud sfa fallback (G)
This parameter is designed to control whether Himmelblaud should fallback to
Single Factor Authentication (SFA) if Multi-Factor Authentication (MFA) isn't
available. This normally is possible during a short window during which MFA
enrollment is available to a new user.
Default:
himmelblaud sfa fallback
no
Example:
himmelblaud sfa fallback
yes
honor change notify privilege (S)
This option can be used to make use of the change notify privilege.
By default notify results are not checked against the file system
permissions.
If "honor change notify privilege" is enabled, a user will only
receive notify results, if he has change notify privilege or
sufficient file system permissions. If a user has the change notify
privilege, he will receive all requested notify results, even if the
user does not have the permissions on the file system.
Default:
honor change notify privilege
no
host msdfs (G)
If set to
yes
, Samba will act as a Dfs server, and allow Dfs-aware clients to browse
Dfs trees hosted on the server.
See also the
msdfs root
share level parameter. For more information on
setting up a Dfs tree on Samba, refer to the MSFDS chapter in the book Samba3-HOWTO.
Default:
host msdfs
yes
hostname lookups (G)
Specifies whether samba should use (expensive)
hostname lookups or use the ip addresses instead. An example place
where hostname lookups are currently used is when checking
the
hosts deny
and
hosts allow
Default:
hostname lookups
no
Example:
hostname lookups
yes
allow hosts
This parameter is a synonym for
hosts allow
hosts allow (S)
A synonym for this parameter is
allow hosts
This parameter is a comma, space, or tab delimited
set of hosts which are permitted to access a service.
If specified in the [global] section then it will
apply to all services, regardless of whether the individual
service has a different setting.
You can specify the hosts by name or IP number. For
example, you could restrict access to only the hosts on a
Class C subnet with something like
allow hosts = 150.203.5.
The full syntax of the list is described in the man
page
hosts_access(5)
. Note that this man
page may not be present on your system, so a brief description will
be given here also.
Note that the localhost address 127.0.0.1 will always
be allowed access unless specifically denied by a
hosts deny
option.
You can also specify hosts by network/netmask pairs and
by netgroup names if your system supports netgroups. The
EXCEPT
keyword can also be used to limit a
wildcard list. The following examples may provide some help:
Example 1: allow all IPs in 150.203.*.*; except one
hosts allow = 150.203. EXCEPT 150.203.6.66
Example 2: allow hosts that match the given network/netmask
hosts allow = 150.203.15.0/255.255.255.0
Example 3: allow a couple of hosts
hosts allow = lapland, arvidsjaur
Example 4: allow only hosts in NIS netgroup "foonet", but
deny access from one particular host
hosts allow = @foonet
hosts deny = pirate
Note
Note that access still requires suitable user-level passwords.
See
testparm
(1)
for a way of testing your host access
to see if it does what you expect.
Default:
hosts allow
# none (i.e., all hosts permitted access)
Example:
hosts allow
150.203.5. myhost.mynet.edu.au
deny hosts
This parameter is a synonym for
hosts deny
hosts deny (S)
The opposite of
hosts allow
- hosts listed here are
NOT
permitted access to
services unless the specific services have their own lists to override
this one. Where the lists conflict, the
allow
list takes precedence.
In the event that it is necessary to deny all by default, use the keyword
ALL (or the netmask
0.0.0.0/0
) and then explicitly specify
to the
hosts allow = hosts allow
parameter those hosts
that should be permitted access.
Default:
hosts deny
# none (i.e., no hosts specifically excluded)
Example:
hosts deny
150.203.4. badhost.mynet.edu.au
idmap backend (G)
The idmap backend provides a plugin interface for Winbind to use
varying backends to store SID/uid/gid mapping tables.
This option specifies the default backend that is used when no special
configuration set, but it is now deprecated in favour of the new
spelling
idmap config * : backend
Default:
idmap backend
tdb
idmap cache time (G)
This parameter specifies the number of seconds that Winbind's
idmap interface will cache positive SID/uid/gid query results. By
default, Samba will cache these results for one week.
Default:
idmap cache time
604800
idmap config DOMAIN : OPTION (G)
ID mapping in Samba is the mapping between Windows SIDs and Unix user
and group IDs. This is performed by Winbindd with a configurable plugin
interface. Samba's ID mapping is configured by options starting with the
idmap config
prefix.
An idmap option consists of the
idmap config
prefix, followed by a domain name or the asterisk character (*),
a colon, and the name of an idmap setting for the chosen domain.
The idmap configuration is hence divided into groups, one group
for each domain to be configured, and one group with the
asterisk instead of a proper domain name, which specifies the
default configuration that is used to catch all domains that do
not have an explicit idmap configuration of their own.
There are three general options available:
backend = backend_name
This specifies the name of the idmap plugin to use as the
SID/uid/gid backend for this domain. The standard backends are
tdb
idmap_tdb
(8)
),
tdb2
idmap_tdb2
(8)
),
ldap
idmap_ldap
(8)
),
rid
idmap_rid
(8)
),
hash
idmap_hash
(8)
),
autorid
idmap_autorid
(8)
),
ad
idmap_ad
(8)
and nss
idmap_nss
(8)
).
The corresponding manual pages contain the details, but
here is a summary.
The first three of these create mappings of their own using
internal unixid counters and store the mappings in a database.
These are suitable for use in the default idmap configuration.
The rid and hash backends use a pure algorithmic calculation
to determine the unixid for a SID. The autorid module is a
mixture of the tdb and rid backend. It creates ranges for
each domain encountered and then uses the rid algorithm for each
of these automatically configured domains individually.
The ad backend uses unix ids stored in Active Directory via
the standard schema extensions. The nss backend reverses
the standard winbindd setup and gets the unix ids via names
from nsswitch which can be useful in an ldap setup.
range = low - high
Defines the available matching uid and gid range for which the
backend is authoritative. For allocating backends, this also
defines the start and the end of the range for allocating
new unique IDs.
winbind uses this parameter to find the backend that is
authoritative for a unix ID to SID mapping, so it must be set
for each individually configured domain and for the default
configuration. The configured ranges must be mutually disjoint.
Note that the low value interacts with the
min domain uid
option!
read only = yes|no
This option can be used to turn the writing backends
tdb, tdb2, and ldap into read only mode. This can be useful
e.g. in cases where a pre-filled database exists that should
not be extended automatically.
The following example illustrates how to configure the
idmap_ad
(8)
backend for the CORP domain and the
idmap_tdb
(8)
backend for all other
domains. This configuration assumes that the admin of CORP assigns
unix ids below 1000000 via the SFU extensions, and winbind is supposed
to use the next million entries for its own mappings from trusted
domains and for local groups for example.
idmap config * : backend = tdb
idmap config * : range = 1000000-1999999

idmap config CORP : backend = ad
idmap config CORP : range = 1000-999999
No default
winbind gid
This parameter is a synonym for
idmap gid
idmap gid (G)
The idmap gid parameter specifies the range of group ids
for the default idmap configuration. It is now deprecated
in favour of
idmap config * : range
See the
idmap config
option.
Default:
idmap gid
Example:
idmap gid
10000-20000
idmap negative cache time (G)
This parameter specifies the number of seconds that Winbind's
idmap interface will cache negative SID/uid/gid query results.
Default:
idmap negative cache time
120
winbind uid
This parameter is a synonym for
idmap uid
idmap uid (G)
The idmap uid parameter specifies the range of user ids for
the default idmap configuration. It is now deprecated in favour
of
idmap config * : range
See the
idmap config
option.
Default:
idmap uid
Example:
idmap uid
10000-20000
include system krb5 conf (G)
Setting this parameter to
no
will prevent
winbind to include the system /etc/krb5.conf file into the krb5.conf file
it creates. See also
create krb5 conf
. This option
only applies to Samba built with MIT Kerberos.
Default:
include system krb5 conf
yes
include (S)
This allows you to include one config file inside another. The file is included literally, as though typed
in place.
It takes the standard substitutions, except
%u
%P
and
%S
The parameter
include = registry
has
a special meaning: It does
not
include
a file named
registry
from the current working
directory, but instead reads the global configuration options
from the registry. See the section on registry-based
configuration for details. Note that this option
automatically activates registry shares.
Default:
include
Example:
include
/usr/local/samba/lib/admin_smb.conf
inherit acls (S)
This parameter is only relevant for filesystems that
do not support standardized NFS4 ACLs but only a POSIX draft ACL
implementation and which implements default ACLs like most filesystems
on Linux. It can be used to ensure that if default ACLs
exist on parent directories, they are always honored when creating a
new file or subdirectory in these parent directories. The default
behavior is to use the unix mode specified when creating the directory.
Enabling this option sets the unix mode to 0777, thus guaranteeing that
the default directory ACLs are propagated.

Note that using the VFS modules acl_xattr or acl_tdb which store native
Windows as meta-data will automatically turn this option on for any
share for which they are loaded, as they require this option to emulate
Windows ACLs correctly.
Default:
inherit acls
no
inherit owner (S)
The ownership of new files and directories
is normally governed by effective uid of the connected user.
This option allows the Samba administrator to specify that
the ownership for new files and directories should be controlled
by the ownership of the parent directory.
Valid options are:
no
Both the Windows (SID) owner and the UNIX (uid) owner of the file are
governed by the identity of the user that created the file.
windows and unix
The Windows (SID) owner and the UNIX (uid) owner of new files and
directories are set to the respective owner of the parent directory.
yes
- a synonym for
windows and unix
unix only
Only the UNIX owner is set to the UNIX owner of the parent directory.
Common scenarios where this behavior is useful is in
implementing drop-boxes, where users can create and edit files but
not delete them and ensuring that newly created files in a user's
roaming profile directory are actually owned by the user.
The
unix only
option effectively
breaks the tie between the Windows owner of a file and the
UNIX owner. As a logical consequence, in this mode,
setting the Windows owner of a file does not modify the UNIX
owner. Using this mode should typically be combined with a
backing store that can emulate the full NT ACL model without
affecting the POSIX permissions, such as the acl_xattr
VFS module, coupled with
acl_xattr:ignore system acls = yes
This can be used to emulate folder quotas, when files are
exposed only via SMB (without UNIX extensions).
The UNIX owner of a directory is locally set
and inherited by all subdirectories and files, and they all
consume the same quota.
Default:
inherit owner
no
inherit permissions (S)
The permissions on new files and directories are normally governed by
create mask
directory mask
force create mode
and
force directory mode
but the boolean inherit permissions parameter overrides this.
New directories inherit the mode of the parent directory,
including bits such as setgid.
New files inherit their read/write bits from the parent directory. Their execute bits continue to be
determined by
map archive
map hidden
and
map system
as usual.
Note that the setuid bit is
never
set via
inheritance (the code explicitly prohibits this).
This can be particularly useful on large systems with
many users, perhaps several thousand, to allow a single [homes]
share to be used flexibly by each user.
Default:
inherit permissions
no
init logon delayed hosts (G)
This parameter takes a list of host names, addresses or networks for
which the initial samlogon reply should be delayed (so other DCs get
preferred by XP workstations if there are any).
The length of the delay can be specified with the
init logon delay
parameter.
Default:
init logon delayed hosts
Example:
init logon delayed hosts
150.203.5. myhost.mynet.de
init logon delay (G)
This parameter specifies a delay in milliseconds for the hosts configured
for delayed initial samlogon with
init logon delayed hosts
Default:
init logon delay
100
interfaces (G)
This option allows you to override the default
network interfaces list that Samba will use for browsing, name
registration and other NetBIOS over TCP/IP (NBT) traffic. By default Samba will query
the kernel for the list of all active interfaces and use any
interfaces except 127.0.0.1 that are broadcast capable.
The option takes a list of interface strings. Each string
can be in any of the following forms:
a network interface name (such as eth0).
This may include shell-like wildcards so eth* will match
any interface starting with the substring "eth"
an IP address. In this case the netmask is
determined from the list of interfaces obtained from the
kernel
an IP/mask pair.
a broadcast/mask pair.
The "mask" parameters can either be a bit length (such
as 24 for a C class network) or a full netmask in dotted
decimal form.
The "IP" parameters above can either be a full dotted
decimal IP address or a hostname which will be looked up via
the OS's normal hostname resolution mechanisms.
By default Samba enables all active interfaces that are broadcast capable
except the loopback adaptor (IP address 127.0.0.1).
In order to support SMB3 multi-channel configurations, smbd understands
some extra parameters which can be appended after the actual interface with
this extended syntax (note that the quoting is important in order to handle the ; and ,
characters):
"interface[;key1=value1[,key2=value2[...]]]"
Known keys are speed, capability, if_index and options. Speed
is specified in bits per second. Known capabilities are RSS and RDMA. The
if_index should be used with care: the values must not coincide with
indexes used by the kernel.
Note that these options are mainly intended for testing and
development rather than for production use. At least on Linux systems,
these values should be auto-detected, but the settings can serve
as last a resort when autodetection is not working or is not available.
The specified values overwrite the auto-detected values.
The possible values for options are
"dynamic" and "nodynamic".
Use this option in combination with setting
bind interfaces only
Use the "dynamic" to have smbd open/close listening sockets on the
interface, when IP addresses are added to or removed from the interface.
Use the "nodynamic" option to ignore any ip add/remove events for
interface.
Please note that when an IP address is removed, connections to that IP address
are also terminated (traditional behaviour has been to keep the TCP flow alive).
Note that dynamically opening/closing listening sockets is only available on some
operating systems (currently Linux).
The first two example below configures three network interfaces corresponding
to the eth0 device and IP addresses 192.168.2.10 and 192.168.3.10.
The netmasks of the latter two interfaces would be set to 255.255.255.0.
The other examples show how per interface extra parameters can be specified.
Notice the possible usage of "," and ";", which makes
the double quoting necessary.
Default:
interfaces
Example:
interfaces
eth0 192.168.2.10/24 192.168.3.10/255.255.255.0
Example:
interfaces
eth0, 192.168.2.10/24; 192.168.3.10/255.255.255.0
Example:
interfaces
"eth0;if_index=65,speed=1000000000,capability=RSS"
Example:
interfaces
"lo;speed=1000000000" "eth0;capability=RSS"
Example:
interfaces
"lo;speed=1000000000" , "eth0;capability=RSS"
Example:
interfaces
"eth0;capability=RSS" , "rdma1;capability=RDMA" ; "rdma2;capability=RSS,capability=RDMA"
Example:
interfaces
"eth0;options=dynamic"
invalid users (S)
This is a list of users that should not be allowed
to login to this service. This is really a
paranoid
check to absolutely ensure an improper setting does not breach
your security.
A name starting with a '@' is interpreted as an NIS
netgroup first (if your system supports NIS), and then as a UNIX
group if the name was not found in the NIS netgroup database.
A name starting with '+' is interpreted only
by looking in the UNIX group database via the NSS getgrnam() interface. A name starting with
'&' is interpreted only by looking in the NIS netgroup database
(this requires NIS to be working on your system). The characters
'+' and '&' may be used at the start of the name in either order
so the value
+&group
means check the
UNIX group database, followed by the NIS netgroup database, and
the value
&+group
means check the NIS
netgroup database, followed by the UNIX group database (the
same as the '@' prefix).
The current servicename is substituted for
%S
This is useful in the [homes] section.
Default:
invalid users
# no invalid users
Example:
invalid users
root fred admin @wheel
iprint server (G)
This parameter is only applicable if
printing
is set to
iprint
If set, this option overrides the ServerName option in the CUPS
client.conf
. This is
necessary if you have virtual samba servers that connect to different CUPS daemons.
Default:
iprint server
""
Example:
iprint server
MYCUPSSERVER
kdc default domain supported enctypes (G)
Set the default value of
msDS-SupportedEncryptionTypes
for service accounts in Active Directory that are missing this value or where
msDS-SupportedEncryptionTypes
is set to 0.
This allows Samba administrators to match the configuration flexibility provided by the
HKEY_LOCAL_MACHINE\System\CurrentControlSet\services\KDC\DefaultDomainSupportedEncTypes
Registry Value on Windows.
Unlike the Windows registry key (which only takes an base-10 number), in Samba this may also be expressed in hexadecimal or as a list of Kerberos encryption type names.
Specified values are ORed together bitwise, and those currently supported consist of:
arcfour-hmac-md5
rc4-hmac
0x4
, or
Known on Windows as Kerberos RC4 encryption
aes128-cts-hmac-sha1-96
aes128-cts
0x8
, or
Known on Windows as Kerberos AES 128 bit encryption
aes256-cts-hmac-sha1-96
aes256-cts
0x10
, or
16
Known on Windows as Kerberos AES 256 bit encryption
aes256-cts-hmac-sha1-96-sk
aes256-cts-sk
0x20
, or
32
Allow AES session keys. When this is set, it indicates to the KDC that AES session keys can be used, even when
aes256-cts
and
aes128-cts
are not set. This allows use of AES keys against hosts otherwise only configured with RC4 for ticket keys (which is the default).
Default:
kdc default domain supported enctypes
# maps to what the software supports currently: arcfour-hmac-md5 aes256-cts-hmac-sha1-96-sk
kdc enable fast (G)
With the Samba 4.16 the embedded Heimdal KDC brings
support for RFC6113 FAST, which wasn't available in
older Samba versions.
This option is mostly for testing and currently only applies
if the embedded Heimdal KDC is used.
Default:
kdc enable fast
yes
kdc force enable rc4 weak session keys (G)
RFC8429
declares that
rc4-hmac
Kerberos ciphers are weak and
there are known attacks on Active Directory use of this
cipher suite.
However for compatibility with Microsoft Windows this option
allows the KDC to assume that regardless of the value set in
a service account's
msDS-SupportedEncryptionTypes
attribute
that a
rc4-hmac
Kerberos session key (as distinct from the ticket key, as
found in a service keytab) can be used if the potentially
older client requests it.
Default:
kdc force enable rc4 weak session keys
no
kdc supported enctypes (G)
On an active directory domain controller, this is the list of supported encryption types for local running kdc.
This allows Samba administrators to remove support for weak/unused encryption types, similar
the configuration flexibility provided by the
Network security: Configure encryption types allowed for Kerberos
GPO/Local Policies/Security Options Value, which results in the
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters\SupportedEncryptionTypes
Registry Value on Windows.
Unlike the Windows registry key (which only takes an base-10 number), in Samba this may also be expressed as hexadecimal or a list of Kerberos encryption type names.
Specified values are ORed together bitwise, and those currently supported consist of:
arcfour-hmac-md5
rc4-hmac
0x4
, or
Known on Windows as Kerberos RC4 encryption
aes128-cts-hmac-sha1-96
aes128-cts
0x8
, or
Known on Windows as Kerberos AES 128 bit encryption
aes256-cts-hmac-sha1-96
aes256-cts
0x10
, or
16
Known on Windows as Kerberos AES 256 bit encryption
Default:
kdc supported enctypes
# maps to what the software supports currently: arcfour-hmac-md5 aes128-cts-hmac-sha1-96 aes256-cts-hmac-sha1-96
keepalive (G)
The value of the parameter (an integer) represents
the number of seconds between
keepalive
packets. If this parameter is zero, no keepalive packets will be
sent. Keepalive packets, if sent, allow the server to tell whether
a client is still present and responding.
Keepalives should, in general, not be needed if the socket
has the SO_KEEPALIVE attribute set on it by default. (see
socket options
).
Basically you should only use this option if you strike difficulties.
Please note this option only applies to SMB1 client connections, and
has no effect on SMB2 clients.
Default:
keepalive
300
Example:
keepalive
600
kerberos encryption types (G)
This parameter determines the encryption types to use when operating
as a Kerberos client. Possible values are
all
strong
, and
legacy
Samba uses a Kerberos library (MIT or Heimdal) to obtain Kerberos
tickets. This library is normally configured outside of Samba, using
the krb5.conf file. This file may also include directives to configure
the encryption types to be used. However, Samba implements Active Directory
protocols and algorithms to locate a domain controller. In order to
force the Kerberos library into using the correct domain controller,
some Samba processes, such as
winbindd
(8)
and
net
(8)
, build a private krb5.conf
file for use by the Kerberos library while being invoked from Samba.
This private file controls all aspects of the Kerberos library operation,
and this parameter controls how the encryption types are configured
within this generated file, and therefore also controls the encryption
types negotiable by Samba.
When set to
all
, all active directory
encryption types are allowed.
When set to
strong
, only AES-based encryption
types are offered. This can be used in hardened environments to prevent
downgrade attacks.
When set to
legacy
, only RC4-HMAC-MD5
is allowed. AVOID using this option, because of
CVE-2022-37966
see
Default:
kerberos encryption types
all
kerberos method (G)
Controls how kerberos tickets are verified.
Valid options are:
secrets only - use only the secrets.tdb for
ticket verification (default)
system keytab - use only the system keytab
for ticket verification
dedicated keytab - use a dedicated keytab
for ticket verification
secrets and keytab - use the secrets.tdb
first, then the system keytab
The major difference between "system keytab" and "dedicated
keytab" is that the latter method relies on kerberos to find the
correct keytab entry instead of filtering based on expected
principals.
When the kerberos method is in "dedicated keytab" mode,
dedicated keytab file
must be set to
specify the location of the keytab file.
Suggested configuration is to use the default value 'secrets only' together with the
sync machine password to keytab
option.
Default:
kerberos method
default
kernel change notify (G)
This parameter specifies whether Samba should ask the
kernel for change notifications in directories so that
SMB clients can refresh whenever the data on the server changes.
This parameter is only used when your kernel supports
change notification to user programs using the inotify interface.
Default:
kernel change notify
yes
kernel oplocks (S)
For UNIXes that support kernel based
oplocks
(currently only Linux), this parameter allows the use of them to be
turned on or off. However, this disables Level II oplocks for clients as
the Linux kernel does not support them properly.
Kernel oplocks support allows Samba
oplocks
to be broken whenever a local UNIX process or NFS operation
accesses a file that
smbd
(8)
has oplocked. This allows complete
data consistency between SMB/CIFS, NFS and local file access (and is
very
cool feature :-).
If you do not need this interaction, you should disable the
parameter on Linux to get Level II oplocks and the associated
performance benefit.
This parameter defaults to
no
and is translated
to a no-op on systems that do not have the necessary kernel support.
Default:
kernel oplocks
no
kernel share modes (S)
This parameter controls whether SMB share modes are
translated into file system specific sharemode calls.
Kernel share modes provide a minimal level of interoperability
with local UNIX processes and NFS operations by preventing
access corresponding to the SMB share modes. This requires
a file system specific VFS module with proper support.
Note that in order to use SMB2 durable file handles on a share,
you have to turn kernel share modes off.
This parameter defaults to
no
. Setting
it to
yes
requires a file system module
that supports file system sharemodes, otherwise attempts to
access files will fail with a sharing violation.
Default:
kernel share modes
no
kpasswd port (G)
Specifies which ports the Kerberos server should listen on for
password changes.
Default:
kpasswd port
464
krb5 port (G)
Specifies which port the KDC should listen on for Kerberos traffic.
Default:
krb5 port
88
lanman auth (G)
This parameter has been deprecated since Samba 4.11 and
support for LanMan (as distinct from NTLM, NTLMv2 or
Kerberos authentication)
will be removed in a future Samba release.
That is, in the future, the current default of
lanman auth = no
will be the enforced behaviour.
This parameter determines whether or not
smbd
(8)
will attempt to
authenticate users or permit password changes
using the LANMAN password hash. If disabled, only clients which support NT
password hashes (e.g. Windows NT/2000 clients, smbclient, but not
Windows 95/98 or the MS DOS network client) will be able to
connect to the Samba host.
The LANMAN encrypted response is easily broken, due to its
case-insensitive nature, and the choice of algorithm. Servers
without Windows 95/98/ME or MS DOS clients are advised to disable
this option.
When this parameter is set to
no
this
will also result in sambaLMPassword in Samba's passdb being
blanked after the next password change. As a result of that
lanman clients won't be able to authenticate, even if lanman
auth is re-enabled later on.
Unlike the
encrypt
passwords
option, this parameter cannot alter client
behaviour, and the LANMAN response will still be sent over the
network. See the
client lanman
auth
to disable this for Samba's clients (such as smbclient)
This parameter is overridden by
ntlm
auth
, so unless that it is also set to
ntlmv1-permitted
or
yes
then only NTLMv2 logins will be permitted and no LM hash will be
stored. All modern clients support NTLMv2, and but some older
clients require special configuration to use it.
This parameter has no impact on the Samba AD DC,
LM authentication is always disabled and no LM password is ever
stored.
Default:
lanman auth
no
large readwrite (G)
This parameter determines whether or not
smbd
(8)
supports the new 64k
streaming read and write variant SMB requests introduced with
Windows 2000. Note that due to Windows 2000 client redirector bugs
this requires Samba to be running on a 64-bit capable operating
system such as IRIX, Solaris or a Linux 2.4 kernel. Can improve
performance by 10% with Windows 2000 clients. Defaults to on. Not as
tested as some other Samba code paths.
Default:
large readwrite
yes
ldap admin dn (G)
The
ldap admin dn
defines the Distinguished Name (DN) name used by Samba to contact
the ldap server when retrieving user account information. The
ldap admin dn
is used
in conjunction with the admin dn password stored in the
private/secrets.tdb
file. See the
smbpasswd
(8)
man page for more information on how to accomplish this.
The
ldap admin dn
requires a fully specified DN. The
ldap suffix
is not appended to the
ldap admin dn
No default
ldap connection timeout (G)
This parameter tells the LDAP library calls which timeout in seconds
they should honor during initial connection establishments to LDAP servers.
It is very useful in failover scenarios in particular. If one or more LDAP
servers are not reachable at all, we do not have to wait until TCP
timeouts are over. This feature must be supported by your LDAP library.
This parameter is different from
ldap timeout
which affects operations on LDAP servers using an existing connection
and not establishing an initial connection.
Default:
ldap connection timeout
ldap debug level (G)
This parameter controls the debug level of the LDAP library
calls. In the case of OpenLDAP, it is the same
bit-field as understood by the server and documented in the
slapd.conf
(5)
manpage.
A typical useful value will be
for tracing function calls.
The debug output from the LDAP libraries appears with the
prefix [LDAP] in Samba's logging output.
The level at which LDAP logging is printed is controlled by the
parameter
ldap debug threshold
Default:
ldap debug level
Example:
ldap debug level
ldap debug threshold (G)
This parameter controls the Samba debug level at which
the ldap library debug output is
printed in the Samba logs. See the description of
ldap debug level
for details.
Default:
ldap debug threshold
10
Example:
ldap debug threshold
ldap delete dn (G)
This parameter specifies whether a delete
operation in the ldapsam deletes the complete entry or only the attributes
specific to Samba.
Default:
ldap delete dn
no
ldap deref (G)
This option controls whether Samba should tell the LDAP library
to use a certain alias dereferencing method. The default is
auto
, which means that the default setting of the
ldap client library will be kept. Other possible values are
never
finding
searching
and
always
. Grab
your LDAP manual for more information.
Default:
ldap deref
auto
Example:
ldap deref
searching
ldap follow referral (G)
This option controls whether to follow LDAP referrals or not when
searching for entries in the LDAP database. Possible values are
on
to enable following referrals,
off
to disable this, and
auto
, to use the libldap default settings.
libldap's choice of following referrals or not is set in
/etc/openldap/ldap.conf with the REFERRALS parameter as documented in
ldap.conf(5).
Default:
ldap follow referral
auto
Example:
ldap follow referral
off
ldap group suffix (G)
This parameter specifies the suffix that is
used for groups when these are added to the LDAP directory.
If this parameter is unset, the value of
ldap suffix
will be used instead. The suffix string is prepended to the
ldap suffix
string so use a partial DN.
Default:
ldap group suffix
Example:
ldap group suffix
ou=Groups
ldap idmap suffix (G)
This parameters specifies the suffix that is used when storing idmap mappings. If this parameter
is unset, the value of
ldap suffix
will be used instead. The suffix
string is prepended to the
ldap suffix
string so use a partial DN.
Default:
ldap idmap suffix
Example:
ldap idmap suffix
ou=Idmap
ldap machine suffix (G)
It specifies where machines should be added to the ldap tree. If this parameter is unset, the value of
ldap suffix
will be used instead. The suffix string is prepended to the
ldap suffix
string so use a partial DN.
Default:
ldap machine suffix
Example:
ldap machine suffix
ou=Computers
ldap max anonymous request size (G)
This parameter specifies the maximum permitted size (in bytes)
for an LDAP request received on an anonymous connection.
If the request size exceeds this limit the request will be
rejected.
Default:
ldap max anonymous request size
256000
Example:
ldap max anonymous request size
500000
ldap max authenticated request size (G)
This parameter specifies the maximum permitted size (in bytes)
for an LDAP request received on an authenticated connection.
If the request size exceeds this limit the request will be
rejected.
Default:
ldap max authenticated request size
16777216
Example:
ldap max authenticated request size
4194304
ldap max search request size (G)
This parameter specifies the maximum permitted size (in bytes)
for an LDAP search request.
If the request size exceeds this limit the request will be
rejected.
Default:
ldap max search request size
256000
Example:
ldap max search request size
4194304
ldap page size (G)
This parameter specifies the number of entries per page.
If the LDAP server supports paged results, clients can
request subsets of search results (pages) instead of the entire list.
This parameter specifies the size of these pages.
Default:
ldap page size
1000
Example:
ldap page size
512
ldap password sync
This parameter is a synonym for
ldap passwd sync
ldap passwd sync (G)
This option is used to define whether or not Samba should sync the LDAP password with the NT
and LM hashes for normal accounts (NOT for workstation, server or domain trusts) on a password
change via SAMBA.
The
ldap passwd sync
can be set to one of three values:
Yes
= Try
to update the LDAP, NT and LM passwords and update the pwdLastSet time.
No
= Update NT and
LM passwords and update the pwdLastSet time.
Only
= Only update
the LDAP password and let the LDAP server do the rest.
Default:
ldap passwd sync
no
ldap replication sleep (G)
When Samba is asked to write to a read-only LDAP replica, we are redirected to talk to the read-write master server.
This server then replicates our changes back to the 'local' server, however the replication might take some seconds,
especially over slow links. Certain client activities, particularly domain joins, can become confused by the 'success'
that does not immediately change the LDAP back-end's data.
This option simply causes Samba to wait a short time, to allow the LDAP server to catch up. If you have a particularly
high-latency network, you may wish to time the LDAP replication with a network sniffer, and increase this value accordingly.
Be aware that no checking is performed that the data has actually replicated.
The value is specified in milliseconds, the maximum value is 5000 (5 seconds).
Default:
ldap replication sleep
1000
ldapsam:editposix (G)
Editposix is an option that leverages ldapsam:trusted to make it simpler to manage a domain controller
eliminating the need to set up custom scripts to add and manage the posix users and groups. This option
will instead directly manipulate the ldap tree to create, remove and modify user and group entries.
This option also requires a running winbindd as it is used to allocate new uids/gids on user/group
creation. The allocation range must be therefore configured.
To use this option, a basic ldap tree must be provided and the ldap suffix parameters must be properly
configured. On virgin servers the default users and groups (Administrator, Guest, Domain Users,
Domain Admins, Domain Guests) can be precreated with the command
net sam
provision
. To run this command the ldap server must be running, Winbindd must be running and
the smb.conf ldap options must be properly configured.

The typical ldap setup used with the
ldapsam:trusted = yes
option
is usually sufficient to use
ldapsam:editposix = yes
as well.
An example configuration can be the following:
encrypt passwords = true
passdb backend = ldapsam

ldapsam:trusted=yes
ldapsam:editposix=yes

ldap admin dn = cn=admin,dc=samba,dc=org
ldap delete dn = yes
ldap group suffix = ou=groups
ldap idmap suffix = ou=idmap
ldap machine suffix = ou=computers
ldap user suffix = ou=users
ldap suffix = dc=samba,dc=org

idmap backend = ldap:"ldap://localhost"

idmap uid = 5000-50000
idmap gid = 5000-50000
This configuration assumes a directory layout like described in the following ldif:
dn: dc=samba,dc=org
objectClass: top
objectClass: dcObject
objectClass: organization
o: samba.org
dc: samba

dn: cn=admin,dc=samba,dc=org
objectClass: simpleSecurityObject
objectClass: organizationalRole
cn: admin
description: LDAP administrator
userPassword: secret

dn: ou=users,dc=samba,dc=org
objectClass: top
objectClass: organizationalUnit
ou: users

dn: ou=groups,dc=samba,dc=org
objectClass: top
objectClass: organizationalUnit
ou: groups

dn: ou=idmap,dc=samba,dc=org
objectClass: top
objectClass: organizationalUnit
ou: idmap

dn: ou=computers,dc=samba,dc=org
objectClass: top
objectClass: organizationalUnit
ou: computers
Default:
ldapsam:editposix
no
ldapsam:trusted (G)
By default, Samba as a Domain Controller with an LDAP backend needs to use the Unix-style NSS subsystem to
access user and group information. Due to the way Unix stores user information in /etc/passwd and /etc/group
this inevitably leads to inefficiencies. One important question a user needs to know is the list of groups he
is member of. The plain UNIX model involves a complete enumeration of the file /etc/group and its NSS
counterparts in LDAP. UNIX has optimized functions to enumerate group membership. Sadly, other functions that
are used to deal with user and group attributes lack such optimization.
To make Samba scale well in large environments, the
ldapsam:trusted = yes
option assumes that the complete user and group database that is relevant to Samba is stored in LDAP with the
standard posixAccount/posixGroup attributes. It further assumes that the Samba auxiliary object classes are
stored together with the POSIX data in the same LDAP object. If these assumptions are met,
ldapsam:trusted = yes
can be activated and Samba can bypass the
NSS system to query user group memberships. Optimized LDAP queries can greatly speed up domain logon and
administration tasks. Depending on the size of the LDAP database a factor of 100 or more for common queries
is easily achieved.
Default:
ldapsam:trusted
no
ldap server require strong auth (G)
The
ldap server require strong auth
defines whether
the ldap server requires ldap traffic to be signed or signed and encrypted (sealed).
Possible values are
no
allow_sasl_without_tls_channel_bindings
and
yes
Windows has
LdapEnforceChannelBinding
under
HKLM\SYSTEM\CurrentControlSet\Services\NTDS\Parameters\
A value of
no
allows simple and sasl binds over
all transports. This matches LdapEnforceChannelBinding=0.
A value of
allow_sasl_without_tls_channel_bindings
allows simple and sasl binds (without sign or seal) over TLS encrypted connections.
Missing tls channel bindings are ignored, so only use this if a value of
yes
is not possible.
Unencrypted connections only allow sasl binds with sign or seal.
This matches LdapEnforceChannelBinding=1.
Before support for tls channel bindings existed in Samba,
a value of
allow_sasl_over_tls
was possible in order
to allow sasl binds without tls channel bindings. This now misleading
as a value of
yes
will now allow sasl binds
with tls channel bindings. Configurations should be changed to
yes
instead or
allow_sasl_without_tls_channel_bindings
if really required. Currently
allow_sasl_over_tls
is just an alias of
allow_sasl_without_tls_channel_bindings
but it will be removed in future versions.
A value of
yes
allows only simple binds
and sasl binds with correct tls channel bindings
over TLS encrypted connections. sasl binds without tls channel bindings
are not allowed. Unencrypted connections only
allow sasl binds with sign or seal. This matches LdapEnforceChannelBinding=2.
Default:
ldap server require strong auth
yes
ldap ssl (G)
This option is used to define whether or not Samba should
use SSL when connecting to the ldap server
This is
NOT
related to
Samba's previous SSL support which was enabled by specifying the
--with-ssl
option to the
configure
script.
LDAP connections should be secured where possible. This may be
done setting
either
this parameter to
start tls
or
by specifying
ldaps://
in
the URL argument of
passdb backend
The
ldap ssl
can be set to one of
two values:
Off
= Never
use SSL when querying the directory.
start tls
= Use
the LDAPv3 StartTLS extended operation (RFC2830) for
communicating with the directory server.
Please note that this parameter does only affect
rpc
methods.
Default:
ldap ssl
start tls
ldap suffix (G)
Specifies the base for all ldap suffixes and for storing the sambaDomain object.
The ldap suffix will be appended to the values specified for the
ldap user suffix
ldap group suffix
ldap machine suffix
, and the
ldap idmap suffix
. Each of these should be given only a DN relative to the
ldap suffix
Default:
ldap suffix
Example:
ldap suffix
dc=samba,dc=org
ldap timeout (G)
This parameter defines the number of seconds that Samba should use as timeout for LDAP operations.
Default:
ldap timeout
15
ldap user suffix (G)
This parameter specifies where users are added to the tree. If this parameter is unset,
the value of
ldap suffix
will be used instead. The suffix
string is prepended to the
ldap suffix
string so use a partial DN.
Default:
ldap user suffix
Example:
ldap user suffix
ou=people
level2 oplocks (S)
This parameter controls whether Samba supports
level2 (read-only) oplocks on a share.
Level2, or read-only oplocks allow Windows NT clients
that have an oplock on a file to downgrade from a read-write oplock
to a read-only oplock once a second client opens the file (instead
of releasing all oplocks on a second open, as in traditional,
exclusive oplocks). This allows all openers of the file that
support level2 oplocks to cache the file for read-ahead only (ie.
they may not cache writes or lock requests) and increases performance
for many accesses of files that are not commonly written (such as
application .EXE files).
Once one of the clients which have a read-only oplock
writes to the file all clients are notified (no reply is needed
or waited for) and told to break their oplocks to "none" and
delete any read-ahead caches.
It is recommended that this parameter be turned on to
speed access to shared executables.
For more discussions on level2 oplocks see the CIFS spec.
Currently, if
kernel oplocks
are supported then
level2 oplocks are not granted (even if this parameter is set to
yes
). Note also, the
oplocks
parameter must be set to
yes
on this share in order for
this parameter to have any effect.
Default:
level2 oplocks
yes
lm announce (G)
This parameter determines if
nmbd
(8)
will produce Lanman announce
broadcasts that are needed by OS/2 clients in order for them to see
the Samba server in their browse list. This parameter can have three
values,
yes
no
, or
auto
. The default is
auto
If set to
no
Samba will never produce these
broadcasts. If set to
yes
Samba will produce
Lanman announce broadcasts at a frequency set by the parameter
lm interval
. If set to
auto
Samba will not send Lanman announce broadcasts by default but will
listen for them. If it hears such a broadcast on the wire it will
then start sending them at a frequency set by the parameter
lm interval
Default:
lm announce
auto
Example:
lm announce
yes
lm interval (G)
If Samba is set to produce Lanman announce
broadcasts needed by OS/2 clients (see the
lm announce
parameter) then this
parameter defines the frequency in seconds with which they will be
made. If this is set to zero then no Lanman announcements will be
made despite the setting of the
lm announce
parameter.
Default:
lm interval
60
Example:
lm interval
120
load printers (G)
A boolean variable that controls whether all
printers in the printcap will be loaded for browsing by default.
See the
printers
section for
more details.
Default:
load printers
yes
local master (G)
This option allows
nmbd
(8)
to try and become a local master browser
on a subnet. If set to
no
then
nmbd
will not attempt to become a local master browser
on a subnet and will also lose in all browsing elections. By
default this value is set to
yes
. Setting this value to
yes
doesn't mean that Samba will
become
the
local master browser on a subnet, just that
nmbd
will
participate
in elections for local master browser.
Setting this value to
no
will cause
nmbd
never
to become a local
master browser.
Default:
local master
yes
lock dir
This parameter is a synonym for
lock directory
lock directory (G)
This option specifies the directory where lock
files will be placed. The lock files are used to implement the
max connections
option.
Note: This option can not be set inside registry
configurations.
The files placed in this directory are not required
across service restarts and can be safely placed on volatile
storage (e.g. tmpfs in Linux)
Default:
lock directory
${prefix}/var/lock
Example:
lock directory
/var/run/samba/locks
locking (S)
This controls whether or not locking will be
performed by the server in response to lock requests from the
client.
If
locking = no
, all lock and unlock
requests will appear to succeed and all lock queries will report
that the file in question is available for locking.
If
locking = yes
, real locking will be performed
by the server.
This option
may
be useful for read-only
filesystems which
may
not need locking (such as
CDROM drives), although setting this parameter of
no
is not really recommended even in this case.
Be careful about disabling locking either globally or in a
specific service, as lack of locking may result in data corruption.
You should never need to set this parameter.
Default:
locking
yes
lock spin time (G)
The time in milliseconds that smbd should
keep waiting to see if a failed lock request can
be granted. This parameter has changed in default
value from Samba 3.0.23 from 10 to 200. The associated
lock spin count
parameter is
no longer used in Samba 3.0.24. You should not need
to change the value of this parameter.
Default:
lock spin time
200
log file (G)
This option allows you to override the name of the Samba log file (also known as the debug file).
This option takes the standard substitutions, allowing you to have separate log files for each user or machine.
No default
Example:
log file
/usr/local/samba/var/log.%m
logging (G)
This parameter configures logging backends. Multiple
backends can be specified at the same time, with different log
levels for each backend. The parameter is a list of backends,
where each backend is specified as backend[:option][@loglevel].
The 'option' parameter can be used to pass backend-specific
options.
The log level for a backend is optional, if it is not set for
a backend, all messages are sent to this backend. The parameter
log level
determines overall log levels,
while the log levels specified here define what is sent to the
individual backends.
When
logging
is set, it overrides the
syslog
and
syslog only
parameters.
Some backends are only available when Samba has been compiled
with the additional libraries. The overall list of logging backends:
syslog
file
systemd
lttng
gpfs
ringbuf
The
ringbuf
backend supports an
optional size argument to change the buffer size used, the default is 1 MB:
ringbuf:size=NBYTES
Default:
logging
Example:
logging
syslog@1 file
debuglevel
This parameter is a synonym for
log level
log level (G)
The value of the parameter (a string) allows the debug level (logging level) to be specified in the
smb.conf
file.
This parameter has been extended since the 2.2.x
series, now it allows one to specify the debug level for multiple
debug classes and distinct logfiles for debug classes. This is to give
greater flexibility in the configuration of the system. The following
debug classes are currently implemented:
all
tdb
printdrivers
lanman
smb
rpc_parse
rpc_srv
rpc_cli
passdb
sam
auth
winbind
vfs
idmap
quota
acls
locking
msdfs
dmapi
registry
scavenger
dns
ldb
tevent
auth_audit
auth_json_audit
kerberos
drs_repl
smb2
smb2_credits
dsdb_audit
dsdb_json_audit
dsdb_password_audit
dsdb_password_json_audit
dsdb_transaction_audit
dsdb_transaction_json_audit
dsdb_group_audit
dsdb_group_json_audit
ldapsrv
Various modules register dynamic debug classes at first usage:
catia
dfs_samba4
extd_audit
fileid
fruit
full_audit
media_harmony
preopen
recycle
shadow_copy
shadow_copy
unityed_media
virusfilter
To configure the logging for specific classes to go into a different
file then
log file
, you can append
@PATH
to the class, eg
log level = 1
full_audit:1@/var/log/audit.log
Authentication and authorization audit information is logged
under the
auth_audit
, and if Samba was not compiled with
--without-json, a JSON representation is logged under
auth_json_audit
Support is comprehensive for all authentication and authorisation
of user accounts in the Samba Active Directory Domain Controller,
as well as the implicit authentication in password changes. In
the file server, NTLM authentication, SMB and RPC authorization is
covered.
Log levels for
auth_audit
and
auth_audit_json
are:
2: Authentication Failure
3: Authentication Success
4: Authorization Success
5: Anonymous Authentication and Authorization Success
Changes to the AD DC
sam.ldb
database are logged under the
dsdb_audit
and a JSON representation is logged under
dsdb_json_audit
Group membership changes to the AD DC
sam.ldb
database are logged under the
dsdb_group_audit
and a JSON representation
is logged under
dsdb_group_json_audit
Log levels for
dsdb_audit
dsdb_json_audit
dsdb_group_audit
dsdb_group_json_audit
and
dsdb_json_audit
are:
5: Database modifications
5: Replicated updates from another DC
Password changes and Password resets in the AD DC are logged
under
dsdb_password_audit
and a JSON
representation is logged under the
dsdb_password_json_audit
. Password changes
will also appears as authentication events via
auth_audit
and
auth_audit_json
Log levels for
dsdb_password_audit
and
dsdb_password_json_audit
are:
5: Successful password changes and resets
Transaction rollbacks and prepare commit failures are logged under
the
dsdb_transaction_audit
and a JSON representation is logged under the
dsdb_transaction_json_audit
Log levels for
dsdb_transaction_audit
and
dsdb_transaction_json
are:
5: Transaction failure (rollback)
10: Transaction success (commit)
Transaction roll-backs are possible in Samba, and whilst
they rarely reflect anything more than the failure of an
individual operation (say due to the add of a conflicting record),
they are possible. Audit logs are already generated and sent to
the system logs before the transaction is complete. Logging the
transaction details allows the identification of password and
sam.ldb
operations that have
been rolled back, and so have not actually persisted.
Warning
Changes to
sam.ldb
made locally by the
root
user with direct access to the
database are not logged to the system logs, but to the
administrator's own console. While less than ideal, any user able
to make such modifications could disable the audit logging in any
case.
Default:
log level
Example:
log level
3 passdb:5 auth:10 winbind:2
Example:
log level
1 full_audit:1@/var/log/audit.log winbind:2
log nt token command (G)
This option can be set to a command that will be called when new nt
tokens are created.
This is only useful for development purposes.
Default:
log nt token command
logon drive (G)
This parameter specifies the local path to which the home directory will be
connected (see
logon home
) and is only used by NT
Workstations.
Note that this option is only useful if Samba is set up as a logon server.
Default:
logon drive
Example:
logon drive
h:
logon home (G)
This parameter specifies the home directory location when a Win95/98 or NT Workstation logs into a Samba PDC.
It allows you to do
C:\>
NET USE H: /HOME
from a command prompt, for example.
This option takes the standard substitutions, allowing you to have separate logon scripts for each user or machine.
This parameter can be used with Win9X workstations to ensure that roaming profiles are stored in a
subdirectory of the user's home directory. This is done in the following way:
logon home = \\%N\%U\profile
This tells Samba to return the above string, with substitutions made when a client requests the info, generally
in a NetUserGetInfo request. Win9X clients truncate the info to \\server\share when a user does
net use /home
but use the whole string when dealing with profiles.
Note that in prior versions of Samba, the
logon path
was returned rather than
logon home
. This broke
net use /home
but allowed profiles outside the home directory. The current implementation is correct, and can be used for
profiles if you use the above trick.
Disable this feature by setting
logon home = ""
- using the empty string.
This option is only useful if Samba is set up as a logon server.
Default:
logon home
\\%N\%U
Example:
logon home
\\remote_smb_server\%U
logon path (G)
This parameter specifies the directory where roaming profiles (Desktop, NTuser.dat, etc) are
stored. Contrary to previous versions of these manual pages, it has nothing to do with Win 9X roaming
profiles. To find out how to handle roaming profiles for Win 9X system, see the
logon home
parameter.
This option takes the standard substitutions, allowing you to have separate logon scripts for each user or
machine. It also specifies the directory from which the "Application Data",
desktop
start menu
network neighborhood
programs
and other
folders, and their contents, are loaded and displayed on your Windows NT client.
The share and the path must be readable by the user for the preferences and directories to be loaded onto the
Windows NT client. The share must be writeable when the user logs in for the first time, in order that the
Windows NT client can create the NTuser.dat and other directories.
Thereafter, the directories and any of the contents can, if required, be made read-only. It is not advisable
that the NTuser.dat file be made read-only - rename it to NTuser.man to achieve the desired effect (a
MAN
datory profile).
Windows clients can sometimes maintain a connection to the [homes] share, even though there is no user logged
in. Therefore, it is vital that the logon path does not include a reference to the homes share (i.e. setting
this parameter to \\%N\homes\profile_path will cause problems).
This option takes the standard substitutions, allowing you to have separate logon scripts for each user or machine.
Warning
Do not quote the value. Setting this as
\\%N\profile\%U
will break profile handling. Where the tdbsam or ldapsam passdb backend
is used, at the time the user account is created the value configured
for this parameter is written to the passdb backend and that value will
over-ride the parameter value present in the smb.conf file. Any error
present in the passdb backend account record must be edited using the
appropriate tool (pdbedit on the command-line, or any other locally
provided system tool).
Note that this option is only useful if Samba is set up as a domain controller.
Disable the use of roaming profiles by setting the value of this parameter to no value.
Take note that even if the default setting in the smb.conf file is the empty string,
any value specified in the user account settings in the passdb backend will over-ride the
effect of setting this parameter to null. Disabling of all roaming profile use
requires that the user account settings must also be blank.
An example of use is:
logon path = \\PROFILESERVER\PROFILE\%U
In this example the use of roaming profiles is disabled (depending also on passdb settings):
logon path =
Default:
logon path
\\%N\%U\profile
logon script (G)
This parameter specifies the batch file (
.bat
) or NT command file
.cmd
) to be downloaded and run on a machine when a user successfully logs in. The file
must contain the DOS style CR/LF line endings. Using a DOS-style editor to create the file is recommended.
The script must be a relative path to the
[netlogon]
service. If the [netlogon]
service specifies a
path
of
/usr/local/samba/netlogon
, and
logon script = STARTUP.BAT
, then the file that will be downloaded is:
/usr/local/samba/netlogon/STARTUP.BAT
The contents of the batch file are entirely your choice. A suggested command would be to add
NET TIME \\SERVER /SET /YES
, to force every machine to synchronize clocks with the
same time server. Another use would be to add
NET USE U: \\SERVER\UTILS
for commonly used utilities, or
NET USE Q: \\SERVER\ISO9001_QA
for example.
Note that it is particularly important not to allow write access to the [netlogon] share, or to grant users
write permission on the batch files in a secure environment, as this would allow the batch files to be
arbitrarily modified and security to be breached.
This option takes the standard substitutions, allowing you to have separate logon scripts for each user or
machine.
This option is only useful if Samba is set up as a logon server in a classic domain controller role.
If Samba is set up as an Active Directory domain controller, LDAP attribute
scriptPath
is used instead. For configurations where
passdb backend = ldapsam
is in use,
this option only defines a default value in case LDAP attribute
sambaLogonScript
is missing.
Default:
logon script
Example:
logon script
scripts\%U.bat
log writeable files on exit (G)
When the network connection between a CIFS client and Samba
dies, Samba has no option but to simply shut down the server
side of the network connection. If this happens, there is a
risk of data corruption because the Windows client did not
complete all write operations that the Windows application
requested. Setting this option to "yes" makes smbd log with
a level 0 message a list of all files that have been opened
for writing when the network connection died. Those are the
files that are potentially corrupted. It is meant as an aid
for the administrator to give him a list of files to do
consistency checks on.
Default:
log writeable files on exit
no
lppause command (S)
This parameter specifies the command to be
executed on the server host in order to stop printing or spooling
a specific print job.
This command should be a program or script which takes
a printer name and job number to pause the print job. One way
of implementing this is by using job priorities, where jobs
having a too low priority won't be sent to the printer.
If a
%p
is given then the printer name
is put in its place. A
%j
is replaced with
the job number (an integer). On HPUX (see
printing=hpux
), if the
-p%p
option is added
to the lpq command, the job will show up with the correct status, i.e.
if the job priority is lower than the set fence priority it will
have the PAUSED status, whereas if the priority is equal or higher it
will have the SPOOLED or PRINTING status.
Note that it is good practice to include the absolute path
in the lppause command as the PATH may not be available to the server.
Currently no default value is given to
this string, unless the value of the
printing
parameter is
SYSV
, in which case the default is :
lp -i %p-%j -H hold
or if the value of the
printing
parameter is
SOFTQ
, then the default is:
qstat -s -j%j -h
Default:
lppause command
# determined by printing parameter
Example:
lppause command
/usr/bin/lpalt %p-%j -p0
lpq cache time (G)
This controls how long lpq info will be cached
for to prevent the
lpq
command being called too
often. A separate cache is kept for each variation of the
lpq
command used by the system, so if you use different
lpq
commands for different users then they won't
share cache information.
The cache files are stored in
/tmp/lpq.xxxx
where xxxx is a hash of the
lpq
command in use.
The default is 30 seconds, meaning that the cached results
of a previous identical
lpq
command will be used
if the cached data is less than 30 seconds old. A large value may
be advisable if your
lpq
command is very slow.
A value of 0 will disable caching completely.
Default:
lpq cache time
30
Example:
lpq cache time
10
lpq command (S)
This parameter specifies the command to be
executed on the server host in order to obtain
lpq
-style printer status information.
This command should be a program or script which
takes a printer name as its only parameter and outputs printer
status information.
Currently nine styles of printer status information
are supported; BSD, AIX, LPRNG, PLP, SYSV, HPUX, QNX, CUPS, and SOFTQ.
This covers most UNIX systems. You control which type is expected
using the
printing =
option.
Some clients (notably Windows for Workgroups) may not
correctly send the connection number for the printer they are
requesting status information about. To get around this, the
server reports on the first printer service connected to by the
client. This only happens if the connection number sent is invalid.
If a
%p
is given then the printer name
is put in its place. Otherwise it is placed at the end of the
command.
Note that it is good practice to include the absolute path
in the
lpq command
as the
$PATH
may not be available to the server. When compiled with
the CUPS libraries, no
lpq command
is
needed because smbd will make a library call to obtain the
print queue listing.
Default:
lpq command
# determined by printing parameter
Example:
lpq command
/usr/bin/lpq -P%p
lpresume command (S)
This parameter specifies the command to be
executed on the server host in order to restart or continue
printing or spooling a specific print job.
This command should be a program or script which takes
a printer name and job number to resume the print job. See
also the
lppause command
parameter.
If a
%p
is given then the printer name
is put in its place. A
%j
is replaced with
the job number (an integer).
Note that it is good practice to include the absolute path
in the
lpresume command
as the PATH may not
be available to the server.
See also the
printing
parameter.
Default: Currently no default value is given
to this string, unless the value of the
printing
parameter is
SYSV
, in which case the default is:
lp -i %p-%j -H resume
or if the value of the
printing
parameter
is
SOFTQ
, then the default is:
qstat -s -j%j -r
Default:
lpresume command
# determined by printing parameter
Example:
lpresume command
/usr/bin/lpalt %p-%j -p2
lprm command (S)
This parameter specifies the command to be
executed on the server host in order to delete a print job.
This command should be a program or script which takes
a printer name and job number, and deletes the print job.
If a
%p
is given then the printer name
is put in its place. A
%j
is replaced with
the job number (an integer).
Note that it is good practice to include the absolute
path in the
lprm command
as the PATH may not be
available to the server.
Examples of use are:
lprm command = /usr/bin/lprm -P%p %j

or

lprm command = /usr/bin/cancel %p-%j
Default:
lprm command
# determined by printing parameter
lsa over netlogon (G)
Setting this deprecated option will allow the RPC server
in the AD DC to answer the LSARPC interface on the
\pipe\netlogon
IPC pipe.
When enabled, this matches the behaviour of Microsoft's
Windows, due to their internal implementation choices.
If it is disabled (the default), the AD DC can offer
improved performance, as the netlogon server is decoupled and
can run as multiple processes.
Default:
lsa over netlogon
no
machine password timeout (G)
If a Samba server is a member of a Windows NT or Active Directory Domain (see the
security = domain
and
security = ads
parameters),
then periodically a running winbindd process will try and change
the MACHINE ACCOUNT PASSWORD stored in the TDB called
secrets.tdb
. This parameter specifies how often this password will be changed, in seconds. The default is one
week (expressed in seconds), the same as a Windows NT Domain member server.
See also
smbpasswd
(8)
and the
security = domain
and
security = ads
parameters.
Default:
machine password timeout
604800
magic output (S)
This parameter specifies the name of a file which will contain output created by a magic script (see the
magic script
parameter below).
Warning
If two clients use the same
magic script
in the same directory the output file content is undefined.
Default:
magic output
# .out
Example:
magic output
myfile.txt
magic script (S)
This parameter specifies the name of a file which,
if opened, will be executed by the server when the file is closed.
This allows a UNIX script to be sent to the Samba host and
executed on behalf of the connected user.
Scripts executed in this way will be deleted upon
completion assuming that the user has the appropriate level
of privilege and the file permissions allow the deletion.
If the script generates output, output will be sent to
the file specified by the
magic output
parameter (see above).
Note that some shells are unable to interpret scripts
containing CR/LF instead of CR as
the end-of-line marker. Magic scripts must be executable
as is
on the host, which for some hosts and
some shells will require filtering at the DOS end.
Magic scripts are
EXPERIMENTAL
and
should
NOT
be relied upon.
Default:
magic script
Example:
magic script
user.csh
mangled names (S)
This controls whether non-DOS names under UNIX
should be mapped to DOS-compatible names ("mangled") and made visible,
or whether non-DOS names should simply be ignored.
See the section on
name mangling
for
details on how to control the mangling process.
Possible option settings are
yes
enables name mangling for all not DOS 8.3 conforming
names.
no
- disables any
name mangling.
illegal (default)
- does
mangling for names with illegal NTFS characters. This
is the most sensible setting for modern clients that
don't use the shortname anymore.
If mangling is used then the mangling method is as follows:
The first (up to) five alphanumeric characters
before the rightmost dot of the filename are preserved, forced
to upper case, and appear as the first (up to) five characters
of the mangled name.
A tilde "~" is appended to the first part of the mangled
name, followed by a two-character unique sequence, based on the
original root name (i.e., the original filename minus its final
extension). The final extension is included in the hash calculation
only if it contains any upper case characters or is longer than three
characters.
Note that the character to use may be specified using
the
mangling char
option, if you don't like '~'.
Files whose UNIX name begins with a dot will be
presented as DOS hidden files. The mangled name will be created as
for other filenames, but with the leading dot removed and "___" as
its extension regardless of actual original extension (that's three
underscores).
The two-digit hash value consists of upper case alphanumeric characters.
This algorithm can cause name collisions only if files
in a directory share the same first five alphanumeric characters.
The probability of such a clash is 1/1300.
The name mangling (if enabled) allows a file to be
copied between UNIX directories from Windows/DOS while retaining
the long UNIX filename. UNIX files can be renamed to a new extension
from Windows/DOS and will retain the same basename. Mangled names
do not change between sessions.
Default:
mangled names
illegal
Example:
mangled names
no
mangle prefix (G)
controls the number of prefix
characters from the original name used when generating
the mangled names. A larger value will give a weaker
hash and therefore more name collisions. The minimum
value is 1 and the maximum value is 6.
mangle prefix is effective only when mangling method is hash2.
Default:
mangle prefix
Example:
mangle prefix
mangling char (S)
This controls what character is used as
the
magic
character in
name mangling
. The
default is a '~' but this may interfere with some software. Use this option to set
it to whatever you prefer. This is effective only when mangling method is hash.
Default:
mangling char
Example:
mangling char
mangling method (G)
controls the algorithm used for the generating
the mangled names. Can take two different values, "hash" and
"hash2". "hash" is the algorithm that was
used in Samba for many years and was the default in Samba 2.2.x "hash2" is
now the default and is newer and considered a better algorithm (generates less collisions) in
the names. Many Win32 applications store the mangled names and so
changing to algorithms must not be done lightly as these applications
may break unless reinstalled.
Default:
mangling method
hash2
Example:
mangling method
hash
map acl inherit (S)
This boolean parameter is only relevant for systems that do not support
standardized NFS4 ACLs but only a POSIX draft implementation of ACLs. Linux
is the only common UNIX system which does still not offer standardized NFS4
ACLs actually. On such systems this parameter controls whether
smbd
(8)
will attempt to map the 'protected'
(don't inherit) flags of the Windows ACLs into an extended attribute called
user.SAMBA_PAI (POSIX draft ACL Inheritance). This parameter requires
support for extended attributes on the filesystem and allows the Windows
ACL editor to store (non-)inheritance information while NT ACLs are mapped
best-effort to the POSIX draft ACLs that the OS and filesystem implements.
Default:
map acl inherit
no
map archive (S)
This controls whether the DOS archive attribute
should be mapped to the UNIX owner execute bit. The DOS archive bit
is set when a file has been modified since its last backup. One
motivation for this option is to keep Samba/your PC from making
any file it touches from becoming executable under UNIX. This can
be quite annoying for shared source code, documents, etc...
Note that this parameter will be ignored if the
store dos attributes
parameter is set, as the DOS archive attribute will then be stored inside a UNIX extended
attribute.
Note that this requires the
create mask
parameter to be set such that owner
execute bit is not masked out (i.e. it must include 100). See the parameter
create mask
for details.
Default:
map archive
yes
map hidden (S)
This controls whether DOS style hidden files should be mapped to the UNIX world execute bit.
Note that this parameter will be ignored if the
store dos attributes
parameter is set, as the DOS hidden attribute will then be stored inside a UNIX extended
attribute.
Note that this requires the
create mask
to be set such that the world execute
bit is not masked out (i.e. it must include 001). See the parameter
create mask
for details.
Default:
map hidden
no
map readonly (S)
This controls how the DOS read only attribute should be mapped from a UNIX filesystem.
This parameter can take three different values, which tell
smbd
(8)
how to display the read only attribute on files, where either
store dos attributes
is set to
No
, or no extended attribute is
present. If
store dos attributes
is set to
yes
then this
parameter is
ignored
. This is a new parameter introduced in Samba version 3.0.21.
The three settings are :
Yes
- The read only DOS attribute is mapped to the inverse of the user
or owner write bit in the unix permission mode set. If the owner write bit is not set, the
read only attribute is reported as being set on the file.
If the read only DOS attribute is set, Samba sets the owner, group and
others write bits to zero. Write bits set in an ACL are ignored by Samba.
If the read only DOS attribute is unset, Samba simply sets the write bit of the
owner to one.
Permissions
- The read only DOS attribute is mapped to the effective permissions of
the connecting user, as evaluated by
smbd
(8)
by reading the unix permissions and filesystem ACL (if present).
If the connecting user does not have permission to modify the file, the read only attribute
is reported as being set on the file.
No
- The read only DOS attribute is unaffected by permissions, and can only be set by
the
store dos attributes
method. This may be useful for exporting mounted CDs.
Note that this parameter will be ignored if the
store dos attributes
parameter is set, as the DOS 'read-only' attribute will then be stored inside a UNIX extended
attribute.
The default has changed to no in Samba release 4.9.0 and above to allow better Windows
fileserver compatibility in a default install. In addition the default setting of
store dos attributes
has been changed to
Yes
in Samba release 4.9.0 and above.
Default:
map readonly
no
map system (S)
This controls whether DOS style system files should be mapped to the UNIX group execute bit.
Note that this parameter will be ignored if the
store dos attributes
parameter is set, as the DOS system attribute will then be stored inside a UNIX extended
attribute.
Note that this requires the
create mask
to be set such that the group
execute bit is not masked out (i.e. it must include 010). See the parameter
create mask
for details.
Default:
map system
no
map to guest (G)
This parameter can take four different values, which tell
smbd
(8)
what to do with user
login requests that don't match a valid UNIX user in some way.
The four settings are :
Never
- Means user login
requests with an invalid password are rejected. This is the
default.
Bad User
- Means user
logins with an invalid password are rejected, unless the username
does not exist, in which case it is treated as a guest login and
mapped into the
guest account
Bad Password
- Means user logins
with an invalid password are treated as a guest login and mapped
into the
guest account
. Note that
this can cause problems as it means that any user incorrectly typing
their password will be silently logged on as "guest" - and
will not know the reason they cannot access files they think
they should - there will have been no message given to them
that they got their password wrong. Helpdesk services will
hate
you if you set the
map to
guest
parameter this way :-).
Bad Uid
- Is only applicable when Samba is configured
in some type of domain mode security (security = {domain|ads}) and means that
user logins which are successfully authenticated but which have no valid Unix
user account (and smbd is unable to create one) should be mapped to the defined
guest account. This was the default behavior of Samba 2.x releases. Note that
if a member server is running winbindd, this option should never be required
because the nss_winbind library will export the Windows domain users and groups
to the underlying OS via the Name Service Switch interface.
Note that this parameter is needed to set up "Guest"
share services. This is because in these modes the name of the resource being
requested is
not
sent to the server until after
the server has successfully authenticated the client so the server
cannot make authentication decisions at the correct time (connection
to the share) for "Guest" shares.
Default:
map to guest
Never
Example:
map to guest
Bad User
max connections (S)
This option allows the number of simultaneous connections to a service to be limited.
If
max connections
is greater than 0 then connections
will be refused if this number of connections to the service are already open. A value
of zero mean an unlimited number of connections may be made.
Record lock files are used to implement this feature. The lock files will be stored in
the directory specified by the
lock directory
option.
Default:
max connections
Example:
max connections
10
max disk size (G)
This option allows you to put an upper limit
on the apparent size of disks. If you set this option to 100
then all shares will appear to be not larger than 100 MB in
size.
Note that this option does not limit the amount of
data you can put on the disk. In the above case you could still
store much more than 100 MB on the disk, but if a client ever asks
for the amount of free disk space or the total disk size then the
result will be bounded by the amount specified in
max
disk size
This option is primarily useful to work around bugs
in some pieces of software that can't handle very large disks,
particularly disks over 1GB in size.
max disk size
of 0 means no limit.
Default:
max disk size
Example:
max disk size
1000
max log size (G)
This option (an integer in kilobytes) specifies the max size the log file should grow to.
Samba periodically checks the size and if it is exceeded it will rename the file, adding
.old
extension.
A size of 0 means no limit.
Default:
max log size
5000
Example:
max log size
1000
max mux (G)
This option controls the maximum number of
outstanding simultaneous SMB operations that Samba tells the client
it will allow. You should never need to set this parameter.
Default:
max mux
50
max open files (G)
This parameter limits the maximum number of
open files that one
smbd
(8)
file
serving process may have open for a client at any one time.
This parameter can be set very high (16384) as Samba uses
only one bit per unopened file. Setting this parameter lower than
16384 will cause Samba to complain and set this value back to
the minimum of 16384, as Windows 7 depends on this number of
open file handles being available.
The limit of the number of open files is usually set
by the UNIX per-process file descriptor limit rather than
this parameter so you should never need to touch this parameter.
Default:
max open files
16384
max print jobs (S)
This parameter limits the maximum number of
jobs allowable in a Samba printer queue at any given moment.
If this number is exceeded,
smbd
(8)
will remote "Out of Space" to the client.
Default:
max print jobs
1000
Example:
max print jobs
5000
max reported print jobs (S)
This parameter limits the maximum number of jobs displayed in a port monitor for
Samba printer queue at any given moment. If this number is exceeded, the excess
jobs will not be shown. A value of zero means there is no limit on the number of
print jobs reported.
Default:
max reported print jobs
Example:
max reported print jobs
1000
max smbd processes (G)
This parameter limits the maximum number of
smbd
(8)
processes concurrently running on a system and is intended
as a stopgap to prevent degrading service to clients in the event that the server has insufficient
resources to handle more than this number of connections. Remember that under normal operating
conditions, each user will have an
smbd
(8)
associated with him or her to handle connections to all
shares from a given host.
For a Samba ADDC running the standard process model this option
limits the number of processes forked to handle requests.
Currently new processes are only forked for ldap and netlogon
requests.
Default:
max smbd processes
Example:
max smbd processes
1000
max stat cache size (G)
This parameter limits the size in memory of any
stat cache
being used
to speed up case insensitive name mappings. It represents
the number of kilobyte (1024) units the stat cache can use.
A value of zero, meaning unlimited, is not advisable due to
increased memory usage. You should not need to change this
parameter.
Default:
max stat cache size
512
Example:
max stat cache size
100
max ttl (G)
This option tells
nmbd
(8)
what the default 'time to live'
of NetBIOS names should be (in seconds) when
nmbd
is
requesting a name using either a broadcast packet or from a WINS server. You should
never need to change this parameter. The default is 3 days.
Default:
max ttl
259200
max wins ttl (G)
This option tells
smbd
(8)
when acting as a WINS server
wins support = yes
) what the maximum
'time to live' of NetBIOS names that
nmbd
will grant will be (in seconds). You should never need to change this
parameter. The default is 6 days (518400 seconds).
Default:
max wins ttl
518400
max xmit (G)
This option controls the maximum packet size
that will be negotiated by Samba's
smbd
(8)
for the SMB1 protocol. The default is 16644, which
matches the behavior of Windows 2000. A value below 2048 is likely to cause problems.
You should never need to change this parameter from its default value.
Default:
max xmit
16644
Example:
max xmit
8192
mdns name (G)
This parameter controls the name that multicast DNS
support advertises as its' hostname.
The default is to use the NETBIOS name which is typically
the hostname in all capital letters.
A setting of mdns will defer the hostname configuration
to the MDNS library that is used.
Default:
mdns name
netbios
message command (G)
This specifies what command to run when the
server receives a WinPopup style message.
This would normally be a command that would
deliver the message somehow. How this is to be done is
up to your imagination.
An example is:
message command = csh -c 'xedit %s;rm %s' &
This delivers the message using
xedit
, then
removes it afterwards.
NOTE THAT IT IS VERY IMPORTANT
THAT THIS COMMAND RETURN IMMEDIATELY
. That's why I
have the '&' on the end. If it doesn't return immediately then
your PCs may freeze when sending messages (they should recover
after 30 seconds, hopefully).
All messages are delivered as the global guest user.
The command takes the standard substitutions, although
%u
won't work (
%U
may be better
in this case).
Apart from the standard substitutions, some additional
ones apply. In particular:
%s
= the filename containing
the message.
%t
= the destination that
the message was sent to (probably the server name).
%f
= who the message
is from.
You could make this command send mail, or whatever else
takes your fancy. Please let us know of any really interesting
ideas you have.
Here's a way of sending the messages as mail to root:
message command = /bin/mail -s 'message from %f on %m' root < %s; rm %s
If you don't have a message command then the message
won't be delivered and Samba will tell the sender there was
an error. Unfortunately WfWg totally ignores the error code
and carries on regardless, saying that the message was delivered.
If you want to silently delete it then try:
message command = rm %s
Default:
message command
Example:
message command
csh -c 'xedit %s; rm %s' &
min domain uid (G)
The integer parameter specifies the minimum uid allowed when mapping a
local account to a domain account.
Note that this option interacts with the configured
idmap ranges
Default:
min domain uid
1000
min print space (S)
This sets the minimum amount of free disk
space that must be available before a user will be able to spool
a print job. It is specified in kilobytes. The default is 0, which
means a user can always spool a print job.
Default:
min print space
Example:
min print space
2000
min receivefile size (G)
This option changes the behavior of
smbd
(8)
when processing SMBwriteX calls. Any incoming
SMBwriteX call on a non-signed SMB/CIFS connection greater than this value will not be processed in the normal way but will
be passed to any underlying kernel recvfile or splice system call (if there is no such
call Samba will emulate in user space). This allows zero-copy writes directly from network
socket buffers into the filesystem buffer cache, if available. It may improve performance
but user testing is recommended. If set to zero Samba processes SMBwriteX calls in the
normal way. To enable POSIX large write support (SMB/CIFS writes up to 16Mb) this option must be
nonzero. The maximum value is 128k. Values greater than 128k will be silently set to 128k.
Note this option will have NO EFFECT if set on a SMB signed connection.
The default is zero, which disables this option.
Default:
min receivefile size
min wins ttl (G)
This option tells
nmbd
(8)
when acting as a WINS server (
wins support = yes
) what the minimum 'time to live'
of NetBIOS names that
nmbd
will grant will be (in
seconds). You should never need to change this parameter. The default
is 6 hours (21600 seconds).
Default:
min wins ttl
21600
mit kdc command (G)
This option specifies the path to the MIT kdc binary.
If the KDC is not installed in the default location and wasn't
correctly detected during build then you should modify this variable and
point it to the correct binary.
Default:
mit kdc command
${prefix}/sbin/krb5kdc
Example:
mit kdc command
/opt/mit/sbin/krb5kdc
msdfs proxy (S)
This parameter indicates that the share is a
stand-in for another CIFS share whose location is specified by
the value of the parameter. When clients attempt to connect to
this share, they are redirected to one or multiple, comma separated
proxied shares using the SMB-Dfs protocol.
Only Dfs roots can act as proxy shares. Take a look at the
msdfs root
and
host msdfs
options to find out how to set up a Dfs root share.
No default
Example:
msdfs proxy
\otherserver\someshare,\otherserver2\someshare
msdfs root (S)
If set to
yes
, Samba treats the
share as a Dfs root and allows clients to browse the
distributed file system tree rooted at the share directory.
Dfs links are specified in the share directory by symbolic
links of the form
msdfs:serverA\\shareA,serverB\\shareB
and so on. For more information on setting up a Dfs tree on
Samba, refer to the MSDFS chapter in the Samba3-HOWTO book.
Default:
msdfs root
no
msdfs shuffle referrals (S)
If set to
yes
, Samba will shuffle
Dfs referrals for a given Dfs link if multiple are available,
allowing for load balancing across clients. For more information
on setting up a Dfs tree on Samba, refer to the MSDFS chapter in
the Samba3-HOWTO book.
Default:
msdfs shuffle referrals
no
multicast dns register (G)
If compiled with proper support for it, Samba will
announce itself with multicast DNS services like for example
provided by the Avahi daemon.
This parameter allows disabling Samba to register
itself.
Default:
multicast dns register
yes
name cache timeout (G)
Specifies the number of seconds it takes before
entries in samba's hostname resolve cache time out. If
the timeout is set to 0. the caching is disabled.
Default:
name cache timeout
660
Example:
name cache timeout
name resolve order (G)
This option is used by the programs in the Samba
suite to determine what naming services to use and in what order
to resolve host names to IP addresses. Its main purpose to is to
control how netbios name resolution is performed. The option takes a space
separated string of name resolution options.
The options are: "lmhosts", "host",
"wins" and "bcast". They cause names to be
resolved as follows:
lmhosts
: Lookup an IP address in the Samba lmhosts file. If the line in lmhosts has
no name type attached to the NetBIOS name (see the manpage for lmhosts for details) then
any name type matches for lookup.
host
: Do a standard host name to IP address resolution, using the system
/etc/hosts
or DNS lookups. This method of name resolution is
operating system depended for instance on IRIX or Solaris this may be controlled by the
/etc/nsswitch.conf
file. Note that this method is used only if the NetBIOS name
type being queried is the 0x20 (server) name type or 0x1c (domain controllers). The latter case is only
useful for active directory domains and results in a DNS query for the SRV RR entry matching
_ldap._tcp.domain.
wins
: Query a name with
the IP address listed in the
WINSSERVER
parameter. If no WINS server has
been specified this method will be ignored.
bcast
: Do a broadcast on
each of the known local interfaces listed in the
interfaces
parameter. This is the least reliable of the name resolution
methods as it depends on the target host being on a locally
connected subnet.
The example below will cause the local lmhosts file to be examined
first, followed by a broadcast attempt, followed by a normal
system hostname lookup.
When Samba is functioning in ADS security mode (
security = ads
it is advised to use following settings for
name resolve order
name resolve order = wins bcast
DC lookups will still be done via DNS, but fallbacks to netbios names will
not inundate your DNS servers with needless queries for DOMAIN<0x1c> lookups.
Default:
name resolve order
lmhosts wins host bcast
Example:
name resolve order
lmhosts bcast host
socket address
This parameter is a synonym for
nbt client socket address
nbt client socket address (G)
This option allows you to control what address Samba
will send NBT client packets from, and process replies using,
including in nmbd.
Setting this option should never be necessary on usual Samba
servers running only one nmbd.
By default Samba will send UDP packets from the OS default address for the destination, and accept replies on 0.0.0.0.
This parameter is deprecated. See
bind interfaces only = Yes
and
interfaces
for the previous behaviour of controlling the normal listening sockets.
Default:
nbt client socket address
0.0.0.0
Example:
nbt client socket address
192.168.2.20
nbtd:wins_prepend1Bto1Cqueries (G)
Normally queries for 0x1C names (all logon servers for a domain)
will return the first address of the 0x1B names (domain master browser
and PDC) as first address in the result list. As many client only use
the first address in the list by default, all clients will use the same
server (the PDC). Windows servers have an option to disable this
behavior (since Windows 2000 Service Pack 2).
Default:
nbtd:wins_prepend1Bto1Cqueries
yes
nbtd:wins_randomize1Clist_mask (G)
If the "nbtd:wins_randomize1Clist" parameter is set to "yes",
then randomizing of the first returned address is based on the
specified netmask. If there are addresses which are in the same subnet
as the client address, the first returned address is randomly chosen
out them. Otherwise the first returned address is randomly chosen out
of all addresses.
Default:
nbtd:wins_randomize1Clist_mask
255.255.255.0
nbtd:wins_wins_randomize1Clist (G)
Normally queries for 0x1C names will return the addresses in the
same order as they're stored in the database, that means first all
addresses which have been directly registered at the local wins server
and then all addresses registered at other servers. Windows servers
have an option to change this behavior and randomize the returned
addresses. Set this parameter to "yes" and Samba will sort the
address list depending on the client address and the matching bits of
the addresses, the first address is randomized based on depending on
the "nbtd:wins_randomize1Clist_mask" parameter.
Default:
nbtd:wins_wins_randomize1Clist
no
nbt port (G)
Specifies which port the server should use for NetBIOS over IP name
services traffic.
Default:
nbt port
137
ncalrpc dir (G)
This directory will hold a series of named pipes to allow RPC over inter-process communication.
This will allow Samba and other unix processes to interact over DCE/RPC without using TCP/IP. Additionally a sub-directory 'np' has restricted permissions, and allows a trusted communication channel between Samba processes
Default:
ncalrpc dir
${prefix}/var/run/ncalrpc
Example:
ncalrpc dir
/var/run/samba/ncalrpc
netbios aliases (G)
This is a list of NetBIOS names that nmbd will
advertise as additional names by which the Samba server is known. This allows one machine
to appear in browse lists under multiple names. If a machine is acting as a browse server
or logon server none of these names will be advertised as either browse server or logon
servers, only the primary name of the machine will be advertised with these capabilities.
Default:
netbios aliases
# empty string (no additional names)
Example:
netbios aliases
TEST TEST1 TEST2
netbios name (G)
This sets the NetBIOS name by which a Samba server is known. By default it is the same as the first component
of the host's DNS name. If a machine is a browse server or logon server this name (or the first component of
the hosts DNS name) will be the name that these services are advertised under.
Note that the maximum length for a NetBIOS name is 15 characters.
There is a bug in Samba that breaks operation of browsing and access to shares if the netbios name
is set to the literal name
PIPE
. To avoid this problem, do not name your Samba
server
PIPE
Default:
netbios name
# machine DNS name
Example:
netbios name
MYNAME
netbios scope (G)
This sets the NetBIOS scope that Samba will
operate under. This should not be set unless every machine
on your LAN also sets this value.
Default:
netbios scope
neutralize nt4 emulation (G)
This option controls whether winbindd sends
the NETLOGON_NEG_NEUTRALIZE_NT4_EMULATION flag in order to bypass
the NT4 emulation of a domain controller.
Typically you should not need set this.
It can be useful for upgrades from NT4 to AD domains.
The behavior can be controlled per netbios domain
by using 'neutralize nt4 emulation:NETBIOSDOMAIN = yes' as option.
Default:
neutralize nt4 emulation
no
nmbd bind explicit broadcast (G)
This option causes
nmbd
(8)
to explicitly bind to the
broadcast address of the local subnets. This is needed to make nmbd
work correctly in combination with the
socket address
option.
You should not need to unset this option.
Default:
nmbd bind explicit broadcast
yes
nsupdate command (G)
This option sets the path to the
nsupdate
command which is used for GSS-TSIG dynamic DNS updates.
Default:
nsupdate command
/usr/bin/nsupdate -g
nt acl support (S)
This boolean parameter controls whether
smbd
(8)
will attempt to map
UNIX permissions into Windows NT access control lists. The UNIX
permissions considered are the traditional UNIX owner and
group permissions, as well as filesystem ACLs set on any files or
directories. This parameter was formally a global parameter in
releases prior to 2.2.2.
Default:
nt acl support
yes
nt hash store (G)
This parameter determines whether or not
samba
(8)
will, as an AD DC, attempt to
store the NT password hash used in NTLM and NTLMv2 authentication for
users in this domain.
If so configured, the Samba Active Directory Domain Controller,
will, except for trust accounts (computers, domain
controllers and inter-domain trusts) the
NOT store the NT hash
for new and changed accounts in the sam.ldb database.
This avoids the storage of an unsalted hash for these
user-created passwords. As a consequence the
arcfour-hmac-md5
Kerberos key type is
also unavailable in the KDC for these users - thankfully
modern clients will select an AES based key
instead.
NOTE: As the password history in Active Directory is
stored as an NT hash (and thus unavailable), a workaround is
used, relying instead on Kerberos password hash values.
This stores three passwords, the current, previous and second previous
password. This allows some checking against reuse.
However as these values are salted, changing the
sAMAccountName, userAccountControl or userPrincipalName of
an account will cause the salt to change. After the rare
combination of both a rename and a password change only the
current password will be recognised for password history
purposes.
The available settings are:
always
- Always store the NT hash
(as machine accounts will also always store an NT hash,
a hash will be stored for all accounts).
This setting may be useful if
ntlm auth
is set to
disabled
for a trial period
never
- Never store the NT hash
for user accounts, only for machine accounts
auto
- Store an NT hash if
ntlm auth
is not set to
disabled
Default:
nt hash store
always
ntlm auth (G)
This parameter determines whether or not
smbd
(8)
will attempt to
authenticate users using the NTLM encrypted password response for
this local passdb (SAM or account database).
If disabled, both NTLM and LanMan authentication against the
local passdb is disabled.
Note that these settings apply only to local users,
authentication will still be forwarded to and NTLM authentication
accepted against any domain we are joined to, and any trusted
domain, even if disabled or if NTLMv2-only is enforced here. To
control NTLM authentication for domain users, this option must
be configured on each DC.
By default with
ntlm auth
set to
ntlmv2-only
only NTLMv2 logins will be
permitted. All modern clients support NTLMv2 by default, but some older
clients will require special configuration to use it.
The primary user of NTLMv1 is MSCHAPv2 for VPNs and 802.1x.
The available settings are:
ntlmv1-permitted
(alias
yes
) - Allow NTLMv1 and above for all clients.
This is the required setting to enable the
lanman auth
parameter.
ntlmv2-only
(alias
no
) - Do not allow NTLMv1 to be used,
but permit NTLMv2.
mschapv2-and-ntlmv2-only
- Only
allow NTLMv1 when the client promises that it is providing
MSCHAPv2 authentication (such as the
ntlm_auth
tool).
disabled
- Do not accept NTLM (or
LanMan) authentication of any level, nor permit
NTLM password changes.
WARNING:
Both Microsoft Windows
and Samba
Read Only Domain Controllers
(RODCs) convert a plain-text LDAP Simple Bind into an NTLMv2
authentication to forward to a full DC. Setting this option
to
disabled
will cause these forwarded
authentications to fail.
Additionally, for Samba acting as an Active Directory
Domain Controller, for user accounts, if
nt hash store
is set to the default setting of
auto
the
NT hash will not be stored
in the sam.ldb database for new users and after a
password change.
The default changed from
yes
to
no
with Samba 4.5. The default changed again
to
ntlmv2-only
with Samba 4.7, however the
behaviour is unchanged.
Default:
ntlm auth
ntlmv2-only
nt pipe support (G)
This boolean parameter controls whether
smbd
(8)
will allow Windows NT
clients to connect to the NT SMB specific
IPC$
pipes. This is a developer debugging option and can be left
alone.
Default:
nt pipe support
yes
ntp signd socket directory (G)
This setting controls the location of the socket that
the NTP daemon uses to communicate with Samba for
signing packets.
If a non-default path is specified here, then it is also necessary
to make NTP aware of the new path using the
ntpsigndsocket
directive in
ntp.conf
Default:
ntp signd socket directory
${prefix}/var/lib/ntp_signd
nt status support (G)
This boolean parameter controls whether
smbd
(8)
will negotiate NT specific status
support with Windows NT/2k/XP clients. This is a developer debugging option and should be left alone.
If this option is set to
no
then Samba offers
exactly the same DOS error codes that versions prior to Samba 2.2.3
reported.
You should not need to ever disable this parameter.
Default:
nt status support
yes
ntvfs handler (S)
This specifies the NTVFS handlers for this share.
unixuid: Sets up user credentials based on POSIX gid/uid.
cifs: Proxies a remote CIFS FS. Mainly useful for testing.
nbench: Filter module that saves data useful to the nbench benchmark suite.
ipc: Allows using SMB for inter process communication. Only used for the IPC$ share.
posix: Maps POSIX FS semantics to NT semantics
print: Allows printing over SMB. This is
LANMAN-style printing, not the be confused with the spoolss
DCE/RPC interface used by later versions of
Windows.
Note that this option is only used when the NTVFS file server
is in use. It is not used with the (default)
s3fs file server.
Default:
ntvfs handler
unixuid, default
null passwords (G)
Allow or disallow client access to accounts that have null passwords.
See also
smbpasswd
(5)
Default:
null passwords
no
obey pam restrictions (G)
When Samba 3.0 is configured to enable PAM support
(i.e. --with-pam), this parameter will control whether or not Samba
should obey PAM's account and session management directives. The
default behavior is to use PAM for clear text authentication only
and to ignore any account or session management. Note that Samba
always ignores PAM for authentication in the case of
encrypt passwords = yes
. The reason
is that PAM modules cannot support the challenge/response
authentication mechanism needed in the presence of SMB password encryption.
Default:
obey pam restrictions
no
old password allowed period (G)
Number of minutes to permit an NTLM login after a password change or reset using the old password. This allows the user to re-cache the new password on multiple clients without disrupting a network reconnection in the meantime.
This parameter only applies when
server role
is set to Active Directory Domain Controller.
Default:
old password allowed period
60
oplock break wait time (G)
This is a tuning parameter added due to bugs in both Windows 9x and WinNT. If Samba responds to a client too
quickly when that client issues an SMB that can cause an oplock break request, then the network client can
fail and not respond to the break request. This tuning parameter (which is set in milliseconds) is the amount
of time Samba will wait before sending an oplock break request to such (broken) clients.
Warning
DO NOT CHANGE THIS PARAMETER UNLESS YOU HAVE READ AND UNDERSTOOD THE SAMBA OPLOCK CODE.
Default:
oplock break wait time
oplocks (S)
This boolean option tells
smbd
whether to
issue oplocks (opportunistic locks) to file open requests on this
share. The oplock code can dramatically (approx. 30% or more) improve
the speed of access to files on Samba servers. It allows the clients
to aggressively cache files locally and you may want to disable this
option for unreliable network environments (it is turned on by
default in Windows NT Servers).
Oplocks may be selectively turned off on certain files with a share. See
the
veto oplock files
parameter. On some systems
oplocks are recognized by the underlying operating system. This
allows data synchronization between all access to oplocked files,
whether it be via Samba or NFS or a local UNIX process. See the
kernel oplocks
parameter for details.
Default:
oplocks
yes
os2 driver map (G)
The parameter is used to define the absolute
path to a file containing a mapping of Windows NT printer driver
names to OS/2 printer driver names. The format is:
= .
For example, a valid entry using the HP LaserJet 5
printer driver would appear as
HP LaserJet 5L = LASERJET.HP
LaserJet 5L
The need for the file is due to the printer driver namespace problem described in
the chapter on Classical Printing in the Samba3-HOWTO book. For more
details on OS/2 clients, please refer to chapter on other clients in the Samba3-HOWTO book.
Default:
os2 driver map
os level (G)
This integer value controls what level Samba advertises itself as for browse elections. The value of this
parameter determines whether
nmbd
(8)
has a chance of becoming a local master browser for the
workgroup
in the local broadcast area.
Note:
By default, Samba will win a local master browsing election over all Microsoft operating
systems except a Windows NT 4.0/2000 Domain Controller. This means that a misconfigured Samba host can
effectively isolate a subnet for browsing purposes. This parameter is largely auto-configured in the Samba-3
release series and it is seldom necessary to manually override the default setting. Please refer to
the chapter on Network Browsing in the Samba-3 HOWTO document for further information regarding the use
of this parameter.
Note:
The maximum value for this parameter is 255. If you use higher values, counting
will start at 0!
Default:
os level
20
Example:
os level
65
pam password change (G)
With the addition of better PAM support in Samba 2.2,
this parameter, it is possible to use PAM's password change control
flag for Samba. If enabled, then PAM will be used for password
changes when requested by an SMB client instead of the program listed in
passwd program
It should be possible to enable this without changing your
passwd chat
parameter for most setups.
Default:
pam password change
no
panic action (G)
This is a Samba developer option that allows a
system command to be called when either
smbd
(8)
or
nmbd
(8)
crashes. This is usually used to
draw attention to the fact that a problem occurred.
Default:
panic action
Example:
panic action
/bin/sleep 90000
passdb backend (G)
This option allows the administrator to chose which backend
will be used for storing user and possibly group information. This allows
you to swap between different storage mechanisms without recompile.
The parameter value is divided into two parts, the backend's name, and a 'location'
string that has meaning only to that particular backed. These are separated
by a : character.
Available backends can include:
smbpasswd
- The old plaintext passdb
backend. Some Samba features will not work if this passdb
backend is used. Takes a path to the smbpasswd file as an
optional argument.
tdbsam
- The TDB based password storage
backend. Takes a path to the TDB as an optional argument (defaults to passdb.tdb
in the
private dir
directory.
ldapsam
- The LDAP based passdb
backend. Takes an LDAP URL as an optional argument (defaults to
ldap://localhost
LDAP connections should be secured where possible. This may be done using either
Start-TLS (see
ldap ssl
) or by
specifying
ldaps://
in
the URL argument.
Multiple servers may also be specified in double-quotes.
Whether multiple servers are supported or not and the exact
syntax depends on the LDAP library you use.
Examples of use are:
passdb backend = tdbsam:/etc/samba/private/passdb.tdb

or multi server LDAP URL with OpenLDAP library:

passdb backend = ldapsam:"ldap://ldap-1.example.com ldap://ldap-2.example.com"

or multi server LDAP URL with Netscape based LDAP library:

passdb backend = ldapsam:"ldap://ldap-1.example.com ldap-2.example.com"
Default:
passdb backend
tdbsam
passdb expand explicit (G)
This parameter controls whether Samba substitutes %-macros in the passdb fields if they are explicitly set. We
used to expand macros here, but this turned out to be a bug because the Windows client can expand a variable
%G_osver% in which %G would have been substituted by the user's primary group.
Default:
passdb expand explicit
no
passwd chat debug (G)
This boolean specifies if the passwd chat script
parameter is run in
debug
mode. In this mode the
strings passed to and received from the passwd chat are printed
in the
smbd
(8)
log with a
debug level
of 100. This is a dangerous option as it will allow plaintext passwords
to be seen in the
smbd
log. It is available to help
Samba admins debug their
passwd chat
scripts
when calling the
passwd program
and should
be turned off after this has been done. This option has no effect if the
pam password change
parameter is set. This parameter is off by default.
Default:
passwd chat debug
no
passwd chat timeout (G)
This integer specifies the number of seconds smbd will wait for an initial
answer from a passwd chat script being run. Once the initial answer is received
the subsequent answers must be received in one tenth of this time. The default it
two seconds.
Default:
passwd chat timeout
passwd chat (G)
This string controls the
"chat"
conversation that takes places between
smbd
(8)
and the local password changing
program to change the user's password. The string describes a
sequence of response-receive pairs that
smbd
(8)
uses to determine what to send to the
passwd program
and what to expect back. If the expected output is not
received then the password is not changed.
This chat sequence is often quite site specific, depending
on what local methods are used for password control.
Note that this parameter only is used if the
unix password sync
parameter is set to
yes
. This sequence is
then called
AS ROOT
when the SMB password in the
smbpasswd file is being changed, without access to the old password
cleartext. This means that root must be able to reset the user's password without
knowing the text of the previous password.
The string can contain the macro
%n
which is substituted
for the new password. The old password (
%o
) is only available when
encrypt passwords
has been disabled.
The chat sequence can also contain the standard macros
\n, \r, \t and \s to give line-feed, carriage-return, tab
and space. The chat sequence string can also contain
a '*' which matches any sequence of characters. Double quotes can
be used to collect strings with spaces in them into a single
string.
If the send string in any part of the chat sequence is a full
stop ".", then no string is sent. Similarly, if the
expect string is a full stop then no string is expected.
If the
pam password change
parameter is set to
yes
, the
chat pairs may be matched in any order, and success is determined by the PAM result, not any particular
output. The \n macro is ignored for PAM conversions.
Default:
passwd chat
*new*password* %n\n *new*password* %n\n *changed*
Example:
passwd chat
"*Enter NEW password*" %n\n "*Reenter NEW password*" %n\n "*Password changed*"
passwd program (G)
The name of a program that can be used to set
UNIX user passwords. Any occurrences of
%u
will be replaced with the user name. The user name is checked for
existence before calling the password changing program.
Also note that many passwd programs insist in
reasonable
passwords, such as a minimum length, or the inclusion
of mixed case chars and digits. This can pose a problem as some clients
(such as Windows for Workgroups) uppercase the password before sending
it.
Note
that if the
unix
password sync
parameter is set to
yes
then this program is called
AS ROOT
before the SMB password in the smbpasswd
file is changed. If this UNIX password change fails, then
smbd
will fail to change the SMB password also
(this is by design).
If the
unix password sync
parameter
is set this parameter
MUST USE ABSOLUTE PATHS
for
ALL
programs called, and must be examined
for security implications. Note that by default
unix
password sync
is set to
no
Default:
passwd program
Example:
passwd program
/bin/passwd %u
password hash gpg key ids (G)
If
samba
is running as an
active directory domain controller, it is possible to store the
cleartext password of accounts in a PGP/OpenGPG encrypted form.
You can specify one or more recipients by key id or user id.
Note that 32bit key ids are not allowed, specify at least 64bit.
The value is stored as 'Primary:SambaGPG' in the
supplementalCredentials
attribute.
As password changes can occur on any domain controller,
you should configure this on each of them. Note that this feature is currently
available only on Samba domain controllers.
This option is only available if
samba
was compiled with
gpgme
support.
You may need to export the
GNUPGHOME
environment variable before starting
samba
It is strongly recommended to only store the public key in this
location. The private key is not used for encryption and should be
only stored where decryption is required.
Being able to restore the cleartext password helps, when they need to be imported
into other authentication systems later (see
samba-tool user getpassword
or you want to keep the passwords in sync with another system, e.g. an OpenLDAP server
(see
samba-tool user syncpasswords
).
While this option needs to be configured on all domain controllers, the
samba-tool user syncpasswords
command should
run on a single domain controller only (typically the PDC-emulator).
Default:
password hash gpg key ids
Example:
password hash gpg key ids
4952E40301FAB41A
Example:
password hash gpg key ids
selftest@samba.example.com
Example:
password hash gpg key ids
selftest@samba.example.com, 4952E40301FAB41A
password hash userPassword schemes (G)
This parameter determines whether or not
samba
(8)
acting as an Active
Directory Domain Controller will attempt to store additional
passwords hash types for the user
The values are stored as 'Primary:userPassword' in the
supplementalCredentials
attribute. The value of this option is a hash type.
The currently supported hash types are:
CryptSHA256
CryptSHA512
Multiple instances of a hash type may be computed and stored.
The password hashes are calculated using the
crypt
(3)
call.
The number of rounds used to compute the hash can be specified by adding
':rounds=xxxx' to the hash type, i.e. CryptSHA512:rounds=4500 would calculate
an SHA512 hash using 4500 rounds. If not specified the Operating System
defaults for
crypt
(3)
are used.
As password changes can occur on any domain controller,
you should configure this on each of them. Note that this feature is
currently available only on Samba domain controllers.
Currently the NT Hash of the password is recorded when these hashes
are calculated and stored. When retrieving the hashes the current value of the
NT Hash is checked against the stored NT Hash. This detects password changes
that have not updated the password hashes. In this case
samba-tool user
will ignore the stored
hash values.
Being able to obtain the hashed password helps, when
they need to be imported into other authentication systems
later (see
samba-tool user
getpassword
) or you want to keep the passwords in
sync with another system, e.g. an OpenLDAP server (see
samba-tool user
syncpasswords
).
Related command:
unix password sync
Default:
password hash userPassword schemes
Example:
password hash userPassword schemes
CryptSHA256
Example:
password hash userPassword schemes
CryptSHA256 CryptSHA512
Example:
password hash userPassword schemes
CryptSHA256:rounds=5000 CryptSHA512:rounds=7000
password server (G)
By specifying the name of a domain controller with this option,
and using
security = [ads|domain]
it is possible to get Samba
to do all its username/password validation using a specific remote server.
Ideally, this option
should not
be used, as the default '*' indicates to Samba
to determine the best DC to contact dynamically, just as all other hosts in an
AD domain do. This allows the domain to be maintained (addition
and removal of domain controllers) without modification to
the smb.conf file. The cryptographic protection on the authenticated RPC calls
used to verify passwords ensures that this default is safe.
It is strongly recommended that you use the
default of '*'
, however if in your particular
environment you have reason to specify a particular DC list, then
the list of machines in this option must be a list of names or IP
addresses of Domain controllers for the Domain. If you use the
default of '*', or list several hosts in the
password server
option then
smbd
will try each in turn till it
finds one that responds. This is useful in case your primary
server goes down.
If the list of servers contains both names/IP's and the '*'
character, the list is treated as a list of preferred
domain controllers, but an auto lookup of all remaining DC's
will be added to the list as well. Samba will not attempt to optimize
this list by locating the closest DC.
If parameter is a name, it is looked up using the
parameter
name resolve order
and so may resolved
by any method and order described in that parameter.
Default:
password server
Example:
password server
NT-PDC, NT-BDC1, NT-BDC2, *
Example:
password server
windc.mydomain.com:389 192.168.1.101 *
directory
This parameter is a synonym for
path
path (S)
This parameter specifies a directory to which
the user of the service is to be given access. In the case of
printable services, this is where print data will spool prior to
being submitted to the host for printing.
For a printable service offering guest access, the service
should be readonly and the path should be world-writeable and
have the sticky bit set. This is not mandatory of course, but
you probably won't get the results you expect if you do
otherwise.
Any occurrences of
%u
in the path
will be replaced with the UNIX username that the client is using
on this connection. Any occurrences of
%m
will be replaced by the NetBIOS name of the machine they are
connecting from. These replacements are very useful for setting
up pseudo home directories for users.
Note that this path will be based on
root dir
if one was specified.
Default:
path
Example:
path
/home/fred
perfcount module (G)
This parameter specifies the perfcount backend to be used when monitoring SMB
operations. Only one perfcount module may be used, and it must implement all of the
apis contained in the smb_perfcount_handler structure defined in smb.h.
No default
pid directory (G)
This option specifies the directory where pid files will be placed.
Default:
pid directory
${prefix}/var/run
Example:
pid directory
/var/run/
posix locking (S)
The
smbd
(8)
daemon maintains an database of file locks obtained by SMB clients. The default behavior is
to map this internal database to POSIX locks. This means that file locks obtained by SMB clients are
consistent with those seen by POSIX compliant applications accessing the files via a non-SMB
method (e.g. NFS or local file access). It is very unlikely that you need to set this parameter
to "no", unless you are sharing from an NFS mount, which is not a good idea in the first place.
Default:
posix locking
yes
postexec (S)
This option specifies a command to be run
whenever the service is disconnected. It takes the usual
substitutions. The command may be run as the root on some
systems.
An interesting example may be to unmount server
resources:
postexec = /etc/umount /cdrom
Default:
postexec
Example:
postexec
echo \"%u disconnected from %S from %m (%I)\" >> /tmp/log
preexec close (S)
This boolean option controls whether a non-zero return code from
preexec
should close the service being connected to.
Default:
preexec close
no
exec
This parameter is a synonym for
preexec
preexec (S)
This option specifies a command to be run whenever
the service is connected to. It takes the usual substitutions.
An interesting example is to send the users a welcome
message every time they log in. Maybe a message of the day? Here
is an example:
preexec = csh -c 'echo \"Welcome to %S!\" |
/usr/local/samba/bin/smbclient -M %m -I %I' &
Of course, this could get annoying after a while :-)
See also
preexec close
and
postexec
Default:
preexec
Example:
preexec
echo \"%u connected to %S from %m (%I)\" >> /tmp/log
prefered master
This parameter is a synonym for
preferred master
preferred master (G)
This boolean parameter controls if
nmbd
(8)
is a preferred master browser for its workgroup.
If this is set to
yes
, on startup,
nmbd
will force
an election, and it will have a slight advantage in winning the election. It is recommended that this
parameter is used in conjunction with
domain master = yes
, so that
nmbd
can guarantee becoming a domain master.
Use this option with caution, because if there are several hosts (whether Samba servers, Windows 95 or NT)
that are preferred master browsers on the same subnet, they will each periodically and continuously attempt
to become the local master browser. This will result in unnecessary broadcast traffic and reduced browsing
capabilities.
Default:
preferred master
auto
prefork backoff increment (G)
This option specifies the number of seconds added to the delay
before a prefork master or worker process is restarted. The
restart is initially zero, the prefork backoff increment is
added to the delay on each restart up to the value specified by
"prefork maximum backoff".
Additionally set the backoff for an individual service by using
"prefork backoff increment: service name"
i.e. "prefork backoff increment:ldap = 2" to set the
backoff increment to 2.
If the backoff increment is 2 and the maximum backoff is 5.
There will be a zero second delay for the first restart. A two
second delay for the second restart. A four second delay for the
third and any subsequent restarts
Default:
prefork backoff increment
10
prefork children (G)
This option controls the number of worker processes that are
started for each service when prefork process model is enabled
(see
samba
(8)
-M)
The prefork children are only started for those services that
support prefork (currently ldap, kdc and netlogon).
For processes that don't support preforking all requests are
handled by a single process for that service.
This should be set to a small multiple of the number of CPU's
available on the server
Additionally the number of prefork children can be specified for
an individual service by using "prefork children: service name"
i.e. "prefork children:ldap = 8" to set the number of ldap
worker processes.
Default:
prefork children
prefork maximum backoff (G)
This option controls the maximum delay before a failed pre-fork
process is restarted.
Default:
prefork maximum backoff
120
preload modules (G)
This is a list of paths to modules that should
be loaded into smbd before a client connects. This improves
the speed of smbd when reacting to new connections somewhat.
Default:
preload modules
Example:
preload modules
/usr/lib/samba/passdb/mysql.so
preserve case (S)
This controls if new filenames are created with the case that the client passes, or if
they are forced to be the
default case
See the section on
NAME MANGLING
for a fuller discussion.
Default:
preserve case
yes
print ok
This parameter is a synonym for
printable
printable (S)
If this parameter is
yes
, then
clients may open, write to and submit spool files on the directory
specified for the service.
Note that a printable service will ALWAYS allow writing
to the service path (user privileges permitting) via the spooling
of print data. The
read only
parameter controls only non-printing access to
the resource.
Default:
printable
no
printcap cache time (G)
This option specifies the number of seconds before the printing
subsystem is again asked for the known printers.
Setting this parameter to 0 disables any rescanning for new
or removed printers after the initial startup.
Default:
printcap cache time
750
Example:
printcap cache time
600
printcap
This parameter is a synonym for
printcap name
printcap name (G)
This parameter may be used to override the compiled-in default printcap name used by the server (usually
/etc/printcap
). See the discussion of the
[printers]
section above for reasons why you might want to do this.
To use the CUPS printing interface set
printcap name = cups
. This should
be supplemented by an additional setting
printing = cups
in the [global]
section.
printcap name = cups
will use the "dummy" printcap
created by CUPS, as specified in your CUPS configuration file.
On System V systems that use
lpstat
to
list available printers you can use
printcap name = lpstat
to automatically obtain lists of available printers. This
is the default for systems that define SYSV at configure time in
Samba (this includes most System V based systems). If
printcap name
is set to
lpstat
on
these systems then Samba will launch
lpstat -v
and
attempt to parse the output to obtain a printer list.
A minimal printcap file would look something like this:
print1|My Printer 1
print2|My Printer 2
print3|My Printer 3
print4|My Printer 4
print5|My Printer 5
where the '|' separates aliases of a printer. The fact that the second alias has a space in
it gives a hint to Samba that it's a comment.
Note
Under AIX the default printcap name is
/etc/qconfig
. Samba will
assume the file is in AIX
qconfig
format if the string
qconfig
appears in the printcap filename.
Default:
printcap name
/etc/printcap
Example:
printcap name
/etc/myprintcap
print command (S)
After a print job has finished spooling to
a service, this command will be used via a
system()
call to process the spool file. Typically the command specified will
submit the spool file to the host's printing subsystem, but there
is no requirement that this be the case. The server will not remove
the spool file, so whatever command you specify should remove the
spool file when it has been processed, otherwise you will need to
manually remove old spool files.
The print command is simply a text string. It will be used
verbatim after macro substitutions have been made:
%s, %f - the path to the spool
file name
%p - the appropriate printer
name
%J - the job
name as transmitted by the client.
%c - The number of printed pages
of the spooled job (if known).
%z - the size of the spooled
print job (in bytes)
The print command
MUST
contain at least
one occurrence of
%s
or
%f
- the
%p
is optional. At the time
a job is submitted, if no printer name is supplied the
%p
will be silently removed from the printer command.
If specified in the [global] section, the print command given
will be used for any printable service that does not have its own
print command specified.
If there is neither a specified print command for a
printable service nor a global print command, spool files will
be created but not processed and (most importantly) not removed.
Note that printing may fail on some UNIXes from the
nobody
account. If this happens then create
an alternative guest account that can print and set the
guest account
in the [global] section.
You can form quite complex print commands by realizing
that they are just passed to a shell. For example the following
will log a print job, print the file, then remove it. Note that
';' is the usual separator for command in shell scripts.
print command = echo Printing %s >>
/tmp/print.log; lpr -P %p %s; rm %s
You may have to vary this command considerably depending
on how you normally print files on your system. The default for
the parameter varies depending on the setting of the
printing
parameter.
Default: For
printing = BSD, AIX, QNX, LPRNG
or PLP :
print command = lpr -r -P%p %s
For
printing = SYSV or HPUX :
print command = lp -c -d%p %s; rm %s
For
printing = SOFTQ :
print command = lp -d%p -s %s; rm %s
For printing = CUPS : If SAMBA is compiled against
libcups, then
printcap = cups
uses the CUPS API to
submit jobs, etc. Otherwise it maps to the System V
commands with the -oraw option for printing, i.e. it
uses
lp -c -d%p -oraw; rm %s
With
printing = cups
and if SAMBA is compiled against libcups, any manually
set print command will be ignored.
No default
Example:
print command
/usr/local/samba/bin/myprintscript %p %s
printer
This parameter is a synonym for
printer name
printer name (S)
This parameter specifies the name of the printer to which print jobs spooled through a printable service
will be sent.
If specified in the [global] section, the printer name given will be used for any printable service that
does not have its own printer name specified.
The default value of the
printer name
may be
lp
on many
systems.
Default:
printer name
Example:
printer name
laserwriter
printing (S)
This parameters controls how printer status information is
interpreted on your system. It also affects the default values for
the
print command
lpq command
lppause command
lpresume command
, and
lprm command
if specified in the
[global] section.
Currently nine printing styles are supported. They are
BSD
AIX
LPRNG
PLP
SYSV
HPUX
QNX
SOFTQ
CUPS
and
IPRINT
Be aware that CUPS and IPRINT are only available if the CUPS
development library was available at the time Samba was compiled
or packaged.
To see what the defaults are for the other print
commands when using the various options use the
testparm
(1)
program.
This option can be set on a per printer basis. Please be
aware however, that you must place any of the various printing
commands (e.g. print command, lpq command, etc...) after defining
the value for the
printing
option since it will
reset the printing commands to default values.
See also the discussion in the
[printers]
section.
See
testparm -v.
for the default
value on your system
Default:
printing
# Depends on the operating system
printjob username (S)
This parameter specifies which user information will be
passed to the printing system. Usually, the username is sent,
but in some cases, e.g. the domain prefix is useful, too.
Default:
printjob username
%U
Example:
printjob username
%D\%U
print notify backchannel (S)
Windows print clients can update print queue status by expecting
the server to open a backchannel SMB connection to them. Due to
client firewall settings this can cause considerable timeouts
and will often fail, as there is no guarantee the client is even
running an SMB server. By default, the Samba print server will
not try to connect back to clients, and will treat corresponding
requests as if the connection back to the client failed.
Default:
print notify backchannel
no
private directory
This parameter is a synonym for
private dir
private dir (G)
This parameters defines the directory
smbd will use for storing such files as
smbpasswd
and
secrets.tdb
Default:
private dir
${prefix}/private
queuepause command (S)
This parameter specifies the command to be
executed on the server host in order to pause the printer queue.
This command should be a program or script which takes
a printer name as its only parameter and stops the printer queue,
such that no longer jobs are submitted to the printer.
This command is not supported by Windows for Workgroups,
but can be issued from the Printers window under Windows 95
and NT.
If a
%p
is given then the printer name
is put in its place. Otherwise it is placed at the end of the command.
Note that it is good practice to include the absolute
path in the command as the PATH may not be available to the
server.
Default:
queuepause command
# determined by printing parameter
Example:
queuepause command
disable %p
queueresume command (S)
This parameter specifies the command to be
executed on the server host in order to resume the printer queue. It
is the command to undo the behavior that is caused by the
previous parameter (
queuepause command
).
This command should be a program or script which takes
a printer name as its only parameter and resumes the printer queue,
such that queued jobs are resubmitted to the printer.
This command is not supported by Windows for Workgroups,
but can be issued from the Printers window under Windows 95
and NT.
If a
%p
is given then the printer name
is put in its place. Otherwise it is placed at the end of the
command.
Note that it is good practice to include the absolute
path in the command as the PATH may not be available to the
server.
Default:
queueresume command
# determined by printing parameter
Example:
queueresume command
enable %p
raw NTLMv2 auth (G)
This parameter has been deprecated since Samba 4.13 and
support for NTLMv2 authentication without NTLMSSP will be removed
in a future Samba release.
That is, in the future, the current default of
raw NTLMv2 auth = no
will be the enforced behaviour.
This parameter determines whether or not
smbd
(8)
will allow SMB1 clients without
extended security (without SPNEGO) to use NTLMv2 authentication.
If this option,
lanman auth
and
ntlm auth
are all disabled,
then only clients with SPNEGO support will be permitted.
That means NTLMv2 is only supported within NTLMSSP.
Default:
raw NTLMv2 auth
no
read list (S)
This is a list of users that are given read-only access to a service. If the connecting user is in this list
then they will not be given write access, no matter what the
read only
option is set
to. The list can include group names using the syntax described in the
invalid users
parameter.
Default:
read list
Example:
read list
mary, @students
read only (S)
An inverted synonym is
writeable
If this parameter is
yes
, then users
of a service may not create or modify files in the service's
directory.
Note that a printable service (
printable = yes
will
ALWAYS
allow writing to the directory
(user privileges permitting), but only via spooling operations.
Default:
read only
yes
read raw (G)
This is ignored if
async smb echo handler
is set,
because this feature is incompatible with raw read SMB requests
If enabled, raw reads allow reads of 65535 bytes in
one packet. This typically provides a major performance benefit for some very, very old clients.
However, some clients either negotiate the allowable
block size incorrectly or are incapable of supporting larger block
sizes, and for these clients you may need to disable raw reads.
In general this parameter should be viewed as a system tuning
tool and left severely alone.
Default:
read raw
yes
realm (G)
This option specifies the kerberos realm to use. The realm is
used as the ADS equivalent of the NT4
domain
. It
is usually set to the DNS name of the kerberos server.
Default:
realm
Example:
realm
mysambabox.mycompany.com
registry shares (G)
This turns on or off support for share definitions read from
registry. Shares defined in
smb.conf
take
precedence over shares with the same name defined in
registry. See the section on registry-based configuration
for details.
Note that this parameter defaults to
no
but it is set to
yes
when
config backend
is set
to
registry
Default:
registry shares
no
Example:
registry shares
yes
reject aes netlogon servers (G)
This option controls whether winbindd requires support
for ServerAuthenticateKerberos support for the netlogon secure channel.
Support for ServerAuthenticateKerberos was added in Windows
starting with Server 2025, it's available in Samba active directory domain controllers
starting with 4.22 with the '
server support krb5 netlogon = yes
' option,
which is disabled by default.
The following flags will be required: NETLOGON_NEG_PASSWORD_SET2,
NETLOGON_NEG_SUPPORTS_KERBEROS_AUTH and NETLOGON_NEG_AUTHENTICATED_RPC.
You can set this to yes if all domain controllers support
ServerAuthenticateKerberos.
This will prevent downgrade attacks.
The behavior can be controlled per netbios domain
by using 'reject aes netlogon servers:NETBIOSDOMAIN = no' as option.
This option overrides the
reject md5 servers
option.
This option overrides the
client use krb5 netlogon
option (if it is effectively off).
Default:
reject aes netlogon servers
no
reject md5 clients (G)
This option is deprecated and will be removed in a future release,
as it is a security problem if not set to "yes" (which will be
the hardcoded behavior in the future).
This option controls whether the netlogon server (currently
only in 'active directory domain controller' mode), will
reject clients which does not support NETLOGON_NEG_SUPPORTS_AES.
Support for NETLOGON_NEG_SUPPORTS_AES was added in Windows
starting with Server 2008R2 and Windows 7, it's available in Samba
starting with 4.0, however third party domain members like NetApp ONTAP
still uses RC4 (HMAC-MD5), see
for more details.
The default changed from 'no' to 'yes', with the patches for
CVE-2022-38023
see
Avoid using this option!
Use an explicit per machine account
server reject md5 schannel:COMPUTERACCOUNT
' instead!
Which is available with the patches for
CVE-2022-38023
see
Samba will log an error in the log files at log level 0
if legacy a client is rejected or allowed without an explicit,
server reject md5 schannel:COMPUTERACCOUNT = no
' option
for the client. The message will indicate
the explicit '
server reject md5 schannel:COMPUTERACCOUNT = no
line to be added, if the legacy client software requires it. (The log level can be adjusted with
CVE_2022_38023:error_debug_level = 1
in order to complain only at a higher log level).
This allows admins to use "no" only for a short grace period,
in order to collect the explicit
server reject md5 schannel:COMPUTERACCOUNT = no
' options.
When set to 'yes' this option overrides the
allow nt4 crypto:COMPUTERACCOUNT
' and
allow nt4 crypto
' options and implies
allow nt4 crypto:COMPUTERACCOUNT = no
'.
This option is over-ridden by the effective value of 'yes' from
the '
server reject aes schannel:COMPUTERACCOUNT
and/or '
server reject aes schannel
' options.
Default:
reject md5 clients
yes
server reject md5 schannel:COMPUTERACCOUNT (G)
If you still have legacy domain members or trusted domains,
which required "reject md5 clients = no" before,
it is possible to specify an explicit exception per computer account
by setting 'server reject md5 schannel:COMPUTERACCOUNT = no'.
Note that COMPUTERACCOUNT has to be the sAMAccountName value of
the computer account (including the trailing '$' sign).
Samba will log a complaint in the log files at log level 0
about the security problem if the option is set to "no",
but the related computer does not require it.
(The log level can be adjusted with
CVE_2022_38023:warn_about_unused_debug_level = 1
in order to complain only at a higher log level).
Samba will log a warning in the log files at log level 5
if a setting is still needed for the specified computer account.
See
CVE-2022-38023
This option overrides the
reject md5 clients
option.
When set to 'yes' this option overrides the
allow nt4 crypto:COMPUTERACCOUNT
' and
allow nt4 crypto
' options and implies
allow nt4 crypto:COMPUTERACCOUNT = no
'.
This option is over-ridden by the effective value of 'yes' from
the '
server reject aes schannel:COMPUTERACCOUNT
and/or '
server reject aes schannel
' options.
Which means '
server reject md5 schannel:COMPUTERACCOUNT = no
is only useful in combination with '
server reject aes schannel:COMPUTERACCOUNT = no
'.
server reject md5 schannel:LEGACYCOMPUTER1$ = no
server reject aes schannel:LEGACYCOMPUTER1$ = no
server reject md5 schannel:NASBOX$ = no
server reject aes schannel:NASBOX$ = no
server reject md5 schannel:LEGACYCOMPUTER2$ = no
server reject aes schannel:LEGACYCOMPUTER2$ = no
No default
reject md5 servers (G)
This option controls whether winbindd requires support
for aes support for the netlogon secure channel.
The following flags will be required NETLOGON_NEG_ARCFOUR,
NETLOGON_NEG_SUPPORTS_AES, NETLOGON_NEG_PASSWORD_SET2 and NETLOGON_NEG_AUTHENTICATED_RPC.
You can set this to yes if all domain controllers support aes.
This will prevent downgrade attacks.
The behavior can be controlled per netbios domain
by using 'reject md5 servers:NETBIOSDOMAIN = no' as option.
The default changed from 'no' to 'yes, with the patches for CVE-2022-38023,
see https://bugzilla.samba.org/show_bug.cgi?id=15240
This option is over-ridden by the
reject aes netlogon servers
option.
This option overrides the
require strong key
option.
Default:
reject md5 servers
yes
remote announce (G)
This option allows you to setup
nmbd
(8)
to periodically announce itself
to arbitrary IP addresses with an arbitrary workgroup name.
This is useful if you want your Samba server to appear in a remote workgroup for
which the normal browse propagation rules don't work. The remote workgroup can be
anywhere that you can send IP packets to.
For example:
remote announce = 192.168.2.255/SERVERS 192.168.4.255/STAFF
the above line would cause
nmbd
to announce itself
to the two given IP addresses using the given workgroup names. If you leave out the
workgroup name, then the one given in the
workgroup
parameter
is used instead.
The IP addresses you choose would normally be the broadcast addresses of the remote
networks, but can also be the IP addresses of known browse masters if your network
config is that stable.
See the chapter on Network Browsing in the Samba-HOWTO book.
Default:
remote announce
remote browse sync (G)
This option allows you to setup
nmbd
(8)
to periodically request
synchronization of browse lists with the master browser of a Samba
server that is on a remote segment. This option will allow you to
gain browse lists for multiple workgroups across routed networks. This
is done in a manner that does not work with any non-Samba servers.
This is useful if you want your Samba server and all local
clients to appear in a remote workgroup for which the normal browse
propagation rules don't work. The remote workgroup can be anywhere
that you can send IP packets to.
For example:
remote browse sync = 192.168.2.255 192.168.4.255
the above line would cause
nmbd
to request the master browser on the
specified subnets or addresses to synchronize their browse lists with
the local server.
The IP addresses you choose would normally be the broadcast
addresses of the remote networks, but can also be the IP addresses
of known browse masters if your network config is that stable. If
a machine IP address is given Samba makes NO attempt to validate
that the remote machine is available, is listening, nor that it
is in fact the browse master on its segment.
The
remote browse sync
may be used on networks
where there is no WINS server, and may be used on disjoint networks where
each network has its own WINS server.
Default:
remote browse sync
rename user script (G)
This is the full pathname to a script that will be run as root by
smbd
(8)
under special circumstances described below.
When a user with admin authority or SeAddUserPrivilege rights renames a user (e.g.: from the NT4 User Manager
for Domains), this script will be run to rename the POSIX user. Two variables,
%uold
and
%unew
, will be substituted with the old and new usernames, respectively. The script should
return 0 upon successful completion, and nonzero otherwise.
Note
The script has all responsibility to rename all the necessary data that is accessible in this posix method.
This can mean different requirements for different backends. The tdbsam and smbpasswd backends will take care
of the contents of their respective files, so the script is responsible only for changing the POSIX username, and
other data that may required for your circumstances, such as home directory. Please also consider whether or
not you need to rename the actual home directories themselves. The ldapsam backend will not make any changes,
because of the potential issues with renaming the LDAP naming attribute. In this case the script is
responsible for changing the attribute that samba uses (uid) for locating users, as well as any data that
needs to change for other applications using the same directory.
Default:
rename user script
require strong key (G)
This option controls whether winbindd requires support
for md5 strong key support for the netlogon secure channel.
The following flags will be required NETLOGON_NEG_STRONG_KEYS,
NETLOGON_NEG_ARCFOUR and NETLOGON_NEG_AUTHENTICATED_RPC.
You can set this to no if some domain controllers only support des.
This might allows weak crypto to be negotiated, may via downgrade attacks.
The behavior can be controlled per netbios domain
by using 'require strong key:NETBIOSDOMAIN = no' as option.
Note for active directory domain this option is hardcoded to 'yes'
This option is over-ridden by the
reject md5 servers
option.
This option overrides the
client schannel
option.
Default:
require strong key
yes
reset on zero vc (G)
This boolean option controls whether an incoming SMB1 session setup
should kill other connections coming from the same IP. This matches
the default Windows 2003 behaviour.

Setting this parameter to yes becomes necessary when you have a flaky
network and windows decides to reconnect while the old connection
still has files with share modes open. These files become inaccessible
over the new connection.

The client sends a zero VC on the new connection, and Windows 2003
kills all other connections coming from the same IP. This way the
locked files are accessible again.

Please be aware that enabling this option will kill
connections behind a masquerading router, and will not trigger
for clients that only use SMB2 or SMB3.
Default:
reset on zero vc
no
restrict anonymous (G)
The setting of this parameter determines whether SAMR and LSA
DCERPC services can be accessed anonymously. This corresponds
to the following Windows Server registry options:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\RestrictAnonymous
The option also affects the browse option which is required by
legacy clients which rely on Netbios browsing. While modern
Windows version should be fine with restricting the access
there could still be applications relying on anonymous access.
Setting
restrict anonymous = 1
will disable anonymous SAMR access.
Setting
restrict anonymous = 2
will, in addition to restricting SAMR access, disallow anonymous
connections to the IPC$ share in general.
Setting
guest ok = yes
on any share
will remove the security advantage.
Default:
restrict anonymous
root
This parameter is a synonym for
root directory
root dir
This parameter is a synonym for
root directory
root directory (G)
The server will
chroot()
(i.e.
Change its root directory) to this directory on startup. This is
not strictly necessary for secure operation. Even without it the
server will deny access to files not in one of the service entries.
It may also check for, and deny access to, soft links to other
parts of the filesystem, or attempts to use ".." in file names
to access other directories (depending on the setting of the
wide links
parameter).
Adding a
root directory
entry other
than "/" adds an extra level of security, but at a price. It
absolutely ensures that no access is given to files not in the
sub-tree specified in the
root directory
option,
including
some files needed for
complete operation of the server. To maintain full operability
of the server you will need to mirror some system files
into the
root directory
tree. In particular
you will need to mirror
/etc/passwd
(or a
subset of it), and any binaries or configuration files needed for
printing (if required). The set of files that must be mirrored is
operating system dependent.
Default:
root directory
Example:
root directory
/homes/smb
root postexec (S)
This is the same as the
postexec
parameter except that the command is run as root. This is useful for
unmounting filesystems (such as CDROMs) after a connection is closed.
Default:
root postexec
root preexec close (S)
This is the same as the
preexec close
parameter except that the command is run as root.
Default:
root preexec close
no
root preexec (S)
This is the same as the
preexec
parameter except that the command is run as root. This is useful for
mounting filesystems (such as CDROMs) when a connection is opened.
Default:
root preexec
rpc big endian (G)
Setting this option will force the RPC client and server to
transfer data in big endian.
If it is disabled, data will be transferred in little endian.
The behaviour is independent of the endianness of the host machine.
Default:
rpc big endian
no
rpc server dynamic port range (G)
This parameter tells the RPC server which port range it is
allowed to use to create a listening socket for LSA, SAM,
Netlogon and others without wellknown tcp ports.
The first value is the lowest number of the port
range and the second the highest.
This applies to RPC servers in all server roles.
Default:
rpc server dynamic port range
49152-65535
rpc server port (G)
Specifies which port the server should listen on for DCE/RPC over TCP/IP traffic.
This controls the default port for all protocols, except for NETLOGON.
If unset, the first available port from
rpc server dynamic port range
is used, e.g. 49152.
The NETLOGON server will use the next available port, e.g. 49153. To change this port use (eg) rpc server port:netlogon = 4000.
Furthermore, all RPC servers can have the port they use specified independenty, with (for example) rpc server port:drsuapi = 5000.
This option applies currently only when
samba
(8)
runs as an active directory domain controller.
The default value 0 causes Samba to select the first available port from
rpc server dynamic port range
Default:
rpc server port
rpc start on demand helpers (G)
This global parameter determines if
samba-dcerpcd
should be started on demand to service named pipe (np) DCE-RPC requests from
smbd
or
winbindd
. This is the
normal case where no startup scripts have been modified to start
samba-dcerpcd
as a daemon.
If
samba-dcerpcd
is started as a daemon
or via a system service manager such as systemd, this parameter
MUST be set to "no", otherwise
samba-dcerpcd
will fail to start.
Default:
rpc start on demand helpers
yes
samba kcc command (G)
This option specifies the path to the Samba KCC command.
This script is used for replication topology replication.
It should not be necessary to modify this option except
for testing purposes or if the
samba_kcc
was installed in a non-default location.
Default:
samba kcc command
${prefix}/sbin/samba_kcc
Example:
samba kcc command
/usr/local/bin/kcc
security mask (S)
This parameter has been removed for Samba 4.0.0.
No default
security (G)
This option affects how clients respond to
Samba and is one of the most important settings in the
smb.conf
file.
Unless
server role
is specified,
the default is
security = user
, as this is
the most common setting, used for a standalone file server or a DC.
The alternatives to
security = user
are
security = ads
or
security = domain
, which support joining Samba to a Windows domain
You should use
security = user
and
map to guest
if you
want to mainly setup shares without a password (guest shares). This
is commonly used for a shared printer server.
The different settings will now be explained.
SECURITY = AUTO
This is the default security setting in Samba, and causes Samba to consult
the
server role
parameter (if set) to determine the security mode.
SECURITY = USER
If
server role
is not specified, this is the default security setting in Samba.
With user-level security a client must first "log-on" with a
valid username and password (which can be mapped using the
username map
parameter). Encrypted passwords (see the
encrypt passwords
parameter) can also
be used in this security mode. Parameters such as
force user
and
guest only
if set are then applied and
may change the UNIX user to use on this connection, but only after
the user has been successfully authenticated.
Note
that the name of the resource being
requested is
not
sent to the server until after
the server has successfully authenticated the client. This is why
guest shares don't work in user level security without allowing
the server to automatically map unknown users into the
guest account
See the
map to guest
parameter for details on doing this.
SECURITY = DOMAIN
This mode will only work correctly if
net
(8)
has been used to add this
machine into a Windows NT Domain. It expects the
encrypt passwords
parameter to be set to
yes
. In this
mode Samba will try to validate the username/password by passing
it to a Windows NT Primary or Backup Domain Controller, in exactly
the same way that a Windows NT Server would do.
Note
that a valid UNIX user must still
exist as well as the account on the Domain Controller to allow
Samba to have a valid UNIX account to map file access to.
Note
that from the client's point
of view
security = domain
is the same
as
security = user
. It only
affects how the server deals with the authentication,
it does not in any way affect what the client sees.
Note
that the name of the resource being
requested is
not
sent to the server until after
the server has successfully authenticated the client. This is why
guest shares don't work in user level security without allowing
the server to automatically map unknown users into the
guest account
See the
map to guest
parameter for details on doing this.
See also the
password server
parameter and
the
encrypt passwords
parameter.
SECURITY = ADS
In this mode, Samba will act as a domain member in an ADS realm. To operate
in this mode, the machine running Samba will need to have Kerberos installed
and configured and Samba will need to be joined to the ADS realm using the
net utility.
Note that this mode does NOT make Samba operate as a Active Directory Domain
Controller.
Note that this forces
require strong key = yes
and
client schannel = yes
for the primary domain.
Read the chapter about Domain Membership in the HOWTO for details.
Default:
security
AUTO
Example:
security
DOMAIN
server addresses (S)
This is a per-share parameter to limit share visibility and
accessibility to specific server IP addresses. Multi-homed servers
can offer a different set of shares per interface.
An empty list means to offer a share on all interfaces.
Default:
server addresses
max protocol
This parameter is a synonym for
server max protocol
protocol
This parameter is a synonym for
server max protocol
server max protocol (G)
The value of the parameter (a string) is the highest
protocol level that will be supported by the server.
Possible values are :
LANMAN1
: First
modern
version of the protocol. Long filename support.
LANMAN2
: Updates to Lanman1 protocol.
NT1
: Current up to date version of the protocol.
Used by Windows NT. Known as CIFS.
SMB2
: Re-implementation of the SMB protocol.
Used by Windows Vista and later versions of Windows. SMB2 has sub protocols available.
SMB2_02
: The earliest SMB2 version.
SMB2_10
: Windows 7 SMB2 version.
By default SMB2 selects the SMB2_10 variant.
SMB3
: The same as SMB2.
Used by Windows 8. SMB3 has sub protocols available.
SMB3_00
: Windows 8 SMB3 version.
SMB3_02
: Windows 8.1 SMB3 version.
SMB3_11
: Windows 10 SMB3 version.
By default SMB3 selects the SMB3_11 variant.
Normally this option should not be set as the automatic
negotiation phase in the SMB protocol takes care of choosing
the appropriate protocol.
Default:
server max protocol
SMB3
Example:
server max protocol
LANMAN1
min protocol
This parameter is a synonym for
server min protocol
server min protocol (G)
This setting controls the minimum protocol version that the server
will allow the client to use.
Normally this option should not be set as the automatic negotiation
phase in the SMB protocol takes care of choosing the appropriate
protocol unless you have legacy clients which are SMB1 capable only.
See
Related command:
server max protocol
for a full list
of available protocols.
Default:
server min protocol
SMB2_02
Example:
server min protocol
NT1
server multi channel support (G)
This boolean parameter controls whether
smbd
(8)
will support
SMB3 multi-channel.
This parameter was added with version 4.4.
Note that this feature was still considered experimental up to 4.14.
Due to dependencies to kernel APIs of Linux or FreeBSD, it's only possible
to use this feature on Linux and FreeBSD for now. For testing this restriction
can be overwritten by specifying
force:server multi channel support=yes
in addition.
This option is enabled by default starting with to 4.15 (on Linux and FreeBSD).
Default:
server multi channel support
yes
server reject aes schannel (G)
This option is experimental for now!
This option controls whether the netlogon server (currently
only in 'active directory domain controller' mode), will
reject clients which do not support ServerAuthenticateKerberos.
Support for ServerAuthenticateKerberos was added in Windows
starting with Server 2025, it's available in Samba starting with 4.22 with the
server support krb5 netlogon = yes
' and
client use krb5 netlogon = yes
' options,
which are disabled by default.
Note this options is not really related to security problems
behind CVE_2022_38023, but it still uses the debug level related
logic and options.
Samba will log an error in the log files at log level 0
if legacy a client is rejected without an explicit,
server reject aes schannel:COMPUTERACCOUNT = no
' option
for the client. The message will indicate
the explicit '
server reject aes schannel:COMPUTERACCOUNT = no
line to be added, if the client software requires it. (The log level can be adjusted with
CVE_2022_38023:error_debug_level = 1
in order to complain only at a higher log level).
Samba will log a message in the log files at log level 5
if a client is allowed without an explicit,
server reject aes schannel:COMPUTERACCOUNT = no
' option
for the client. The message will indicate
the explicit '
server reject aes schannel:COMPUTERACCOUNT = no
line to be added, if the client software requires it. (The log level can be adjusted with
NETLOGON_AES:usage_debug_level = 0
in order to complain only at a lower or higher log level).
This can we used to prepare the configuration before changing to
server reject aes schannel = yes
Admins can use
server reject aes schannel:COMPUTERACCOUNT = no/yes
' options in
order to have more control
When set to 'yes' this option overrides the
server reject md5 schannel:COMPUTERACCOUNT
' and
reject md5 clients
' options and implies
server reject md5 schannel:COMPUTERACCOUNT = no
'.
This option interacts with the '
server support krb5 netlogon
' option.
For now '
server reject aes schannel
is EXPERIMENTAL and should not be configured explicitly.
Default:
server reject aes schannel
no
Example:
server reject aes schannel
yes
server reject aes schannel:COMPUTERACCOUNT (G)
If the time has come and most domain members or trusted domains
support ServerAuthenticateKerberos, admins may want to use "server reject aes schannel = yes".
It is possible to specify an explicit exception per computer account
by setting 'server reject aes schannel:COMPUTERACCOUNT = no'.
Note that COMPUTERACCOUNT has to be the sAMAccountName value of
the computer account (including the trailing '$' sign).
Note this options is not really related to security problems
behind CVE_2022_38023, but it still uses the debug level related
logic and options.
Samba will log a complaint in the log files at log level 0
about the security problem if the option is set to "no",
but the related computer does not require it.
(The log level can be adjusted with
CVE_2022_38023:warn_about_unused_debug_level = 1
in order to complain only at a higher log level).
Samba will log a warning in the log files at log level 5
if a setting is still needed for the specified computer account.
This option overrides the
server reject aes schannel
option.
When set to 'yes' this option overrides the
server reject md5 schannel:COMPUTERACCOUNT
' and
reject md5 clients
' options and implies
server reject md5 schannel:COMPUTERACCOUNT = no
'.
server reject aes schannel:LEGACYCOMPUTER1$ = no
server reject aes schannel:NASBOX$ = no
server reject aes schannel:LEGACYCOMPUTER2$ = no
server reject aes schannel:HIGHPRIVACYSRV$ = yes
No default
server role (G)
This option determines the basic operating mode of a Samba
server and is one of the most important settings in the
smb.conf
file.
The default is
server role = auto
, as causes
Samba to operate according to the
security
setting, or if not
specified as a simple file server that is not connected to any domain.
The alternatives are
server role = standalone
or
server role = member server
, which support joining Samba to a Windows domain, along with
server role = domain controller
, which run Samba as a Windows domain controller.
You should use
server role = standalone
and
map to guest
if you
want to mainly setup shares without a password (guest shares). This
is commonly used for a shared printer server.
SERVER ROLE = AUTO
This is the default server role in Samba, and causes Samba to consult
the
security
parameter (if set) to determine the server role, giving compatible behaviours to previous Samba versions.
SERVER ROLE = STANDALONE
If
security
is also not specified, this is the default security setting in Samba.
In standalone operation, a client must first "log-on" with a
valid username and password (which can be mapped using the
username map
parameter) stored on this machine. Encrypted passwords (see the
encrypt passwords
parameter) are by default
used in this security mode. Parameters such as
force user
and
guest only
if set are then applied and
may change the UNIX user to use on this connection, but only after
the user has been successfully authenticated.
SERVER ROLE = MEMBER SERVER
This mode will only work correctly if
net
(8)
has been used to add this
machine into a Windows Domain. It expects the
encrypt passwords
parameter to be set to
yes
. In this
mode Samba will try to validate the username/password by passing
it to a Windows or Samba Domain Controller, in exactly
the same way that a Windows Server would do.
Note
that a valid UNIX user must still
exist as well as the account on the Domain Controller to allow
Samba to have a valid UNIX account to map file access to. Winbind can provide this.
SERVER ROLE = CLASSIC PRIMARY DOMAIN CONTROLLER
This mode of operation runs a classic Samba primary domain
controller, providing domain logon services to Windows and Samba
clients of an NT4-like domain. Clients must be joined to the domain to
create a secure, trusted path across the network. There must be
only one PDC per NetBIOS scope (typically a broadcast network or
clients served by a single WINS server).
SERVER ROLE = CLASSIC BACKUP DOMAIN CONTROLLER
This mode of operation runs a classic Samba backup domain
controller, providing domain logon services to Windows and Samba
clients of an NT4-like domain. As a BDC, this allows
multiple Samba servers to provide redundant logon services to a
single NetBIOS scope.
SERVER ROLE = ACTIVE DIRECTORY DOMAIN CONTROLLER
This mode of operation runs Samba as an active directory
domain controller, providing domain logon services to Windows and
Samba clients of the domain. This role requires special
configuration, see the
Samba4
HOWTO
SERVER ROLE = IPA PRIMARY DOMAIN CONTROLLER
This mode of operation runs Samba in a hybrid mode for IPA
domain controller, providing forest trust to Active Directory.
This role requires special configuration performed by IPA installers
and should not be used manually by any administrator.
Default:
server role
AUTO
Example:
server role
ACTIVE DIRECTORY DOMAIN CONTROLLER
server schannel require seal (G)
This option is deprecated and will be removed in future,
as it is a security problem if not set to "yes" (which will be
the hardcoded behavior in future).
This option controls whether the netlogon server, will reject the usage
of netlogon secure channel without privacy/enryption.
The option is modelled after the registry key available on Windows.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\RequireSeal=2
Avoid using this option!
Use the per computer account specific option
server schannel require seal:COMPUTERACCOUNT
' instead!
Which is available with the patches for
CVE-2022-38023
see
Samba will log an error in the log files at log level 0
if legacy a client is rejected or allowed without an explicit,
server schannel require seal:COMPUTERACCOUNT = no
' option
for the client. The message will indicate
the explicit '
server schannel require seal:COMPUTERACCOUNT = no
line to be added, if the legacy client software requires it. (The log level can be adjusted with
CVE_2022_38023:error_debug_level = 1
in order to complain only at a higher log level).
This allows admins to use "no" only for a short grace period,
in order to collect the explicit
server schannel require seal:COMPUTERACCOUNT = no
' options.
When set to 'yes' this option overrides the
server require schannel:COMPUTERACCOUNT
' and
server schannel
' options and implies
server require schannel:COMPUTERACCOUNT = yes
'.
This option is over-ridden by the
server schannel require seal:COMPUTERACCOUNT
option.
Default:
server schannel require seal
yes
server schannel require seal:COMPUTERACCOUNT (G)
If you still have legacy domain members, which required "server schannel require seal = no" before,
it is possible to specify explicit exception per computer account
by using 'server schannel require seal:COMPUTERACCOUNT = no' as option.
Note that COMPUTERACCOUNT has to be the sAMAccountName value of
the computer account (including the trailing '$' sign).
Samba will log a complaint in the log files at log level 0
about the security problem if the option is set to "no",
but the related computer does not require it.
(The log level can be adjusted with
CVE_2022_38023:warn_about_unused_debug_level = 1
in order to complain only at a higher log level).
Samba will warn in the log files at log level 5,
if a setting is still needed for the specified computer account.
See
CVE-2022-38023
This option overrides the '
server schannel require seal
' option.
When set to 'yes' this option overrides the
server require schannel:COMPUTERACCOUNT
' and
server schannel
' options and implies
server require schannel:COMPUTERACCOUNT = yes
'.
server require schannel seal:LEGACYCOMPUTER1$ = no
server require schannel seal:NASBOX$ = no
server require schannel seal:LEGACYCOMPUTER2$ = no
No default
server schannel (G)
This option is deprecated and will be removed in future,
as it is a security problem if not set to "yes" (which will be
the hardcoded behavior in future).
Avoid using this option!
Use explicit '
server require schannel:COMPUTERACCOUNT = no
' instead!
Samba will log an error in the log files at log level 0
if legacy a client is rejected or allowed without an explicit,
server require schannel:COMPUTERACCOUNT = no
' option
for the client. The message will indicate
the explicit '
server require schannel:COMPUTERACCOUNT = no
line to be added, if the legacy client software requires it. (The log level can be adjusted with
CVE_2020_1472:error_debug_level = 1
in order to complain only at a higher log level).
This allows admins to use "auto" only for a short grace period,
in order to collect the explicit
server require schannel:COMPUTERACCOUNT = no
' options.
See
CVE-2020-1472(ZeroLogon)
This option is over-ridden by the
server require schannel:COMPUTERACCOUNT
option.
This option is over-ridden by the effective value of 'yes' from
the '
server schannel require seal:COMPUTERACCOUNT
and/or '
server schannel require seal
' options.
Default:
server schannel
yes
server require schannel:COMPUTERACCOUNT (G)
If you still have legacy domain members, which required "server schannel = auto" before,
it is possible to specify explicit exception per computer account
by using 'server require schannel:COMPUTERACCOUNT = no' as option.
Note that COMPUTERACCOUNT has to be the sAMAccountName value of
the computer account (including the trailing '$' sign).
Samba will complain in the log files at log level 0,
about the security problem if the option is not set to "no",
but the related computer is actually using the netlogon
secure channel (schannel) feature.
(The log level can be adjusted with
CVE_2020_1472:warn_about_unused_debug_level = 1
in order to complain only at a higher log level).
Samba will warn in the log files at log level 5,
if a setting is still needed for the specified computer account.
See
CVE-2020-1472(ZeroLogon)
This option overrides the
server schannel
option.
This option is over-ridden by the effective value of 'yes' from
the '
server schannel require seal:COMPUTERACCOUNT
and/or '
server schannel require seal
' options.
Which means '
server require schannel:COMPUTERACCOUNT = no
is only useful in combination with '
server schannel require seal:COMPUTERACCOUNT = no
server require schannel:LEGACYCOMPUTER1$ = no
server require schannel seal:LEGACYCOMPUTER1$ = no
server require schannel:NASBOX$ = no
server require schannel seal:NASBOX$ = no
server require schannel:LEGACYCOMPUTER2$ = no
server require schannel seal:LEGACYCOMPUTER2$ = no
No default
server services (G)
This option contains the services that the Samba daemon will
run.
An entry in the
smb.conf
file can either
override the previous value completely or entries can be removed from
or added to it by prefixing them with
or
Default:
server services
s3fs, rpc, nbt, wrepl, ldap, cldap, kdc, drepl, ft_scanner, winbindd, ntp_signd, kcc, dnsupdate, dns
Example:
server services
-s3fs, +smb
server signing (G)
This controls whether the client is allowed or required to use SMB1 and SMB2 signing. Possible values
are
default
auto
mandatory
and
disabled
By default, and when smb signing is set to
default
, smb signing is required when
server role
is
active directory
domain controller
and disabled otherwise.
When set to auto, SMB1 signing is offered, but not enforced.
When set to mandatory, SMB1 signing is required and if set
to disabled, SMB signing is not offered either.
For the SMB2 protocol, by design, signing cannot be disabled. In the case
where SMB2 is negotiated, if this parameter is set to
disabled
it will be treated as
auto
. Setting it to
mandatory
will still require SMB2 clients to use signing.
Default:
server signing
default
server smb3 encryption algorithms (G)
This parameter specifies the availability and order of
encryption algorithms which are available for negotiation in the SMB3_11 dialect.
It is also possible to remove individual algorithms from the default list,
by prefixing them with '-'. This can avoid having to specify a hardcoded list.
Note: that the removal of AES-128-CCM from the list will result
in SMB3_00 and SMB3_02 being unavailable, as it is the default and only
available algorithm for these dialects.
Default:
server smb3 encryption algorithms
AES-128-GCM, AES-128-CCM, AES-256-GCM, AES-256-CCM
Example:
server smb3 encryption algorithms
AES-256-GCM
Example:
server smb3 encryption algorithms
-AES-128-GCM -AES-128-CCM
server smb encrypt (S)
This parameter controls whether a remote client is allowed or required
to use SMB encryption. It has different effects depending on whether
the connection uses SMB1 or SMB2 and newer:
If the connection uses SMB1, then this option controls the use
of a Samba-specific extension to the SMB protocol introduced in
Samba 3.2 that makes use of the Unix extensions.
If the connection uses SMB2 or newer, then this option controls
the use of the SMB-level encryption that is supported in SMB
version 3.0 and above and available in Windows 8 and newer.
This parameter can be set globally and on a per-share bases.
Possible values are
off
if_required
desired
and
required
A special value is
default
which is
the implicit default setting of
if_required
Effects for SMB1
The Samba-specific encryption of SMB1 connections is an
extension to the SMB protocol negotiated as part of the UNIX
extensions. SMB encryption uses the GSSAPI (SSPI on Windows)
ability to encrypt and sign every request/response in a SMB
protocol stream. When enabled it provides a secure method of
SMB/CIFS communication, similar to an ssh protected session, but
using SMB/CIFS authentication to negotiate encryption and
signing keys. Currently this is only supported smbclient of by
Samba 3.2 and newer, and hopefully soon Linux CIFSFS and MacOS/X
clients. Windows clients do not support this feature.
This may be set on a per-share
basis, but clients may chose to encrypt the entire session, not
just traffic to a specific share. If this is set to mandatory
then all traffic to a share
must
be encrypted once the connection has been made to the share.
The server would return "access denied" to all non-encrypted
requests on such a share. Selecting encrypted traffic reduces
throughput as smaller packet sizes must be used (no huge UNIX
style read/writes allowed) as well as the overhead of encrypting
and signing all the data.
If SMB encryption is selected, Windows style SMB signing (see
the
server signing
option) is no longer
necessary, as the GSSAPI flags use select both signing and
sealing of the data.
When set to auto or default, SMB encryption is offered, but not
enforced. When set to mandatory, SMB encryption is required and
if set to disabled, SMB encryption can not be negotiated.
Effects for SMB2 and newer
Native SMB transport encryption is available in SMB version 3.0
or newer. It is only offered by Samba if
server max protocol
is set to
SMB3
or newer.
Clients supporting this type of encryption include
Windows 8 and newer,
Windows server 2012 and newer,
and smbclient of Samba 4.1 and newer.
The protocol implementation offers various options:
The capability to perform SMB encryption can be
negotiated during protocol negotiation.
Data encryption can be enabled globally. In that case,
an encryption-capable connection will have all traffic
in all its sessions encrypted. In particular all share
connections will be encrypted.
Data encryption can also be enabled per share if not
enabled globally. For an encryption-capable connection,
all connections to an encryption-enabled share will be
encrypted.
Encryption can be enforced. This means that session
setups will be denied on non-encryption-capable
connections if data encryption has been enabled
globally. And tree connections will be denied for
non-encryption capable connections to shares with data
encryption enabled.
These features can be controlled with settings of
server smb encrypt
as follows:
Leaving it as default, explicitly setting
default
, or setting it to
if_required
globally will enable
negotiation of encryption but will not turn on
data encryption globally or per share.
Setting it to
desired
globally
will enable negotiation and will turn on data encryption
on sessions and share connections for those clients
that support it.
Setting it to
required
globally
will enable negotiation and turn on data encryption
on sessions and share connections. Clients that do
not support encryption will be denied access to the
server.
Setting it to
off
globally will
completely disable the encryption feature for all
connections. Setting
server smb encrypt =
required
for individual shares (while it's
globally off) will deny access to this shares for all
clients.
Setting it to
desired
on a share
will turn on data encryption for this share for clients
that support encryption if negotiation has been
enabled globally.
Setting it to
required
on a share
will enforce data encryption for this share if
negotiation has been enabled globally. I.e. clients that
do not support encryption will be denied access to the
share.
Note that this allows per-share enforcing to be
controlled in Samba differently from Windows:
In Windows,
RejectUnencryptedAccess
is a global setting, and if it is set, all shares with
data encryption turned on
are automatically enforcing encryption. In order to
achieve the same effect in Samba, one
has to globally set
server smb encrypt
to
if_required
, and then set all shares
that should be encrypted to
required
Additionally, it is possible in Samba to have some
shares with encryption
required
and some other shares with encryption only
desired
, which is not possible in
Windows.
Setting it to
off
or
if_required
for a share has
no effect.
Default:
server smb encrypt
default
server smb3 signing algorithms (G)
This parameter specifies the availability and order of
signing algorithms which are available for negotiation in the SMB3_11 dialect.
It is also possible to remove individual algorithms from the default list,
by prefixing them with '-'. This can avoid having to specify a hardcoded list.
Note: that the removal of AES-128-CMAC from the list will result
in SMB3_00 and SMB3_02 being unavailable, and the removal of HMAC-SHA256
will result in SMB2_02 and SMB2_10 being unavailable, as these are the default and only
available algorithms for these dialects.
Default:
server smb3 signing algorithms
AES-128-GMAC, AES-128-CMAC, HMAC-SHA256
Example:
server smb3 signing algorithms
AES-128-CMAC, HMAC-SHA256
Example:
server smb3 signing algorithms
-AES-128-CMAC
server smb transports (G)
Specifies which transports and ports the server should listen on for SMB traffic.
The order matters only for mDNS registrations, the first
'tcp' or 'nbt' port is used for that.
The transport 'tcp' uses raw tcp with a 4 byte length header per SMB PDU.
The default port for 'tcp' is 445. Other ports can be specified by adding it
after ':', e.g. 'tcp:1445'.
The transport 'nbt' uses netbios framing on top of tcp per SMB PDU.
The default port for 'nbt' is 139. Other ports can be specified by adding it
after ':', e.g. 'nbt:1139'.
The transport 'quic' uses the quic protocol on top of udp.
The default port for 'quic' is 443. Other ports can be specified by adding it
after ':', e.g. 'quic:1443'.
The following options are also relevant:
tls enabled
tls cafile
tls certfile
and
tls keyfile
If the files pointed to by
tls cafile
tls certfile
and
tls keyfile
all do not exist,
a self-signed tls certificate is generated automatically at startup.
Note: 'quic' requires the quic.ko kernel module for Linux from
Linux versions may support it natively.
Numerical ports are handled as 'tcp' except port '139' is handled as 'nbt'.
Note that's currently a limit of 10 unique transports, all others will
be ignored.
Default:
server smb transports
tcp, nbt
Example:
server smb transports
445
Example:
server smb transports
tcp, tcp:1445
Example:
server smb transports
8000, nbt:1139
Example:
server smb transports
tcp, quic, nbt
Example:
server smb transports
+quic
smb ports (G)
This is a synonym for
server smb transports
No default
server string (G)
This controls what string will show up in the printer comment box in print
manager and next to the IPC connection in
net view
. It
can be any string that you wish to show to your users.
It also sets what will appear in browse lists next
to the machine name.
%v
will be replaced with the Samba
version number.
%h
will be replaced with the
hostname.
Default:
server string
Samba %v
Example:
server string
University of GNUs Samba Server
server support krb5 netlogon (G)
This option is experimental for now!
This option controls whether the netlogon server (currently
only in 'active directory domain controller' mode), will
provide support for ServerAuthenticateKerberos.
Support for ServerAuthenticateKerberos was added in Windows
starting with Server 2025, it's available in Samba starting with 4.22 with the
server support krb5 netlogon = yes
' and
client use krb5 netlogon = yes
' options,
which are disabled by default.
This option interacts with the
server reject aes schannel:COMPUTERACCOUNT = yes
' and
server reject aes schannel = yes
' options.
Default:
server support krb5 netlogon
no
Example:
server support krb5 netlogon
yes
set primary group script (G)
Thanks to the Posix subsystem in NT a Windows User has a
primary group in addition to the auxiliary groups. This script
sets the primary group in the unix user database when an
administrator sets the primary group from the windows user
manager or when fetching a SAM with
net rpc
vampire
%u
will be replaced
with the user whose primary group is to be set.
%g
will be replaced with the group to
set.
Default:
set primary group script
Example:
set primary group script
/usr/sbin/usermod -g '%g' '%u'
set quota command (G)
The
set quota command
should only be used
whenever there is no operating system API available from the OS that
samba can use.
This option is only available if Samba was compiled with
quota support.
This parameter should specify the path to a script that
can set quota for the specified arguments.
The specified script should take the following arguments:
1 - path to where the quota needs to be set.
This needs to be interpreted relative to the current working
directory that the script may also check for.
2 - quota type
1 - user quotas
2 - user default quotas (uid = -1)
3 - group quotas
4 - group default quotas (gid = -1)
3 - id (uid for user, gid for group, -1 if N/A)
4 - quota state (0 = disable, 1 = enable, 2 = enable and enforce)
5 - block softlimit
6 - block hardlimit
7 - inode softlimit
8 - inode hardlimit
9(optional) - block size, defaults to 1024
The script should output at least one line of data on success. And nothing on failure.
Default:
set quota command
Example:
set quota command
/usr/local/sbin/set_quota
share:fake_fscaps (S)
This is needed to support some special applications that makes use of
filesystem specific features like sparse files or block reflink copy.
With
share:fake_fscaps = 64
the SPARSE_FILES (0x40) file system capability flag is set.
With
share:fake_fscaps = 134217728
the SUPPORTS_BLOCK_REFCOUNTING (0x8000000) file system capability flag
is set. As of this writing, filesystems that support this feature are
BTRFS, XFS and ZFS.
The complete list can be found in MS-FSCC 2.5.1
FileFsAttributeInformation. Note that only decimal values can be used
in the configuration.
Default:
share:fake_fscaps
short preserve case (S)
This boolean parameter controls if new files which conform to 8.3 syntax, that is all in upper case and of
suitable length, are created upper case, or if they are forced to be the
default case
This option can be use with
preserve case = yes
to permit long filenames
to retain their case, while short names are lowered.
See the section on
NAME MANGLING
Default:
short preserve case
yes
show add printer wizard (G)
With the introduction of MS-RPC based printing support
for Windows NT/2000 client in Samba 2.2, a "Printers..." folder will
appear on Samba hosts in the share listing. Normally this folder will
contain an icon for the MS Add Printer Wizard (APW). However, it is
possible to disable this feature regardless of the level of privilege
of the connected user.
Under normal circumstances, the Windows NT/2000 client will
open a handle on the printer server with OpenPrinterEx() asking for
Administrator privileges. If the user does not have administrative
access on the print server (i.e is not root or has granted the
SePrintOperatorPrivilege), the OpenPrinterEx()
call fails and the client makes another open call with a request for
a lower privilege level. This should succeed, however the APW
icon will not be displayed.
Disabling the
show add printer wizard
parameter will always cause the OpenPrinterEx() on the server
to fail. Thus the APW icon will never be displayed.
Note
This does not prevent the same user from having
administrative privilege on an individual printer.
Default:
show add printer wizard
yes
shutdown script (G)
This a full path name to a script called by
smbd
(8)
that should
start a shutdown procedure.
If the connected user possesses the
SeRemoteShutdownPrivilege
right, this command will be run as root.
The %z %t %r %f variables are expanded as follows:
%z
will be substituted with the
shutdown message sent to the server.
%t
will be substituted with the
number of seconds to wait before effectively starting the
shutdown procedure.
%r
will be substituted with the
switch
-r
. It means reboot after shutdown
for NT.
%f
will be substituted with the
switch
-f
. It means force the shutdown
even if applications do not respond for NT.
Shutdown script example:
#!/bin/bash

time=$2
let time="${time} / 60"
let time="${time} + 1"

/sbin/shutdown $3 $4 +$time $1 &
Shutdown does not return so we need to launch it in background.
Default:
shutdown script
Example:
shutdown script
/usr/local/samba/sbin/shutdown %m %t %r %f
unix extensions
This parameter is a synonym for
smb1 unix extensions
smb1 unix extensions (G)
This boolean parameter controls whether Samba
implements the SMB1/CIFS UNIX extensions, as defined by HP.
These extensions enable Samba to better serve UNIX SMB1/CIFS clients
by supporting features such as symbolic links, hard links, etc...
These extensions require a similarly enabled client, and are of
no current use to Windows clients.
Note if this parameter is turned on, the
wide links
parameter will automatically be disabled.
See the parameter
allow insecure wide links
if you wish to change this coupling between the two parameters.
Default:
smb1 unix extensions
yes
smb2 disable lock sequence checking (G)
This boolean parameter controls whether
smbd
(8)
will disable
lock sequence checking even for multi-channel connections
as well as durable handles.
The [MS-SMB2] specification (under 3.3.5.14 Receiving an SMB2 LOCK Request)
documents that a server should do lock sequence if Open.IsResilient or Open.IsDurable
or Open.IsPersistent is TRUE or if Connection.Dialect belongs to the SMB 3.x dialect
family and Connection.ServerCapabilities includes SMB2_GLOBAL_CAP_MULTI_CHANNEL.
But Windows Server (at least up to v2004) only does these checks
for the Open.IsResilient and Open.IsPersistent.
That means they do not implement the behavior specified
in [MS-SMB2].
By default Samba behaves according to the specification
and implements lock sequence checking when multi-channel is used.
Warning: Only enable this option if existing clients can't
handle lock sequence checking for handles without Open.IsResilient and Open.IsPersistent.
And it turns out that the Windows Server behavior is required.
Note: it's likely that this option will be removed again
if future Windows versions change their behavior.
Note: Samba does not implement Open.IsResilient and Open.IsPersistent yet.
Default:
smb2 disable lock sequence checking
no
Example:
smb2 disable lock sequence checking
yes
smb2 disable oplock break retry (G)
This boolean parameter controls whether
smbd
(8)
will trigger
smb2 oplock break notification retries when using
server multi channel support = yes
The [MS-SMB2] specification documents that a server should
send smb2 oplock break notification retries on all available channel
to the given client.
But Windows Server versions (at least up to 2019) do not send
smb2 oplock break notification retries on channel failures.
That means they do not implement the behavior specified
in [MS-SMB2].
By default Samba behaves according to the specification
and send smb2 oplock break notification retries.
Warning: Only enable this option if existing clients can't
handle possible retries and it turns out that the Windows Server
behavior is required.
Note: it's likely that this option gets removed again
if future Windows versions change their behavior.
Note: this only applies to oplocks and not SMB2 leases.
Default:
smb2 disable oplock break retry
no
Example:
smb2 disable oplock break retry
yes
smb2 leases (G)
This boolean option tells
smbd
whether to
globally negotiate SMB2 leases on file open requests. Leasing is an SMB2-only
feature which allows clients to aggressively cache files locally above and
beyond the caching allowed by SMB1 oplocks.
This is only available with
oplocks = yes
and
kernel oplocks = no
Default:
smb2 leases
yes
smb2 max credits (G)
This option controls the maximum number of outstanding simultaneous SMB2 operations
that Samba tells the client it will allow. This is similar to the
max mux
parameter for SMB1. You should never need to set this parameter.
The default is 8192 credits, which is the same as a Windows 2008R2 SMB2 server.
Default:
smb2 max credits
8192
smb2 max read (G)
This option specifies the protocol value that
smbd
(8)
will return to a client, informing the client of the largest
size that may be returned by a single SMB2 read call.
The maximum is 8388608 bytes (8MiB), which is the same as a Windows Server 2012 r2.
Please note that the default is 8MiB, but it's limit is based on the
smb2 dialect (64KiB for SMB == 2.0, 8MiB for SMB >= 2.1 with LargeMTU).
Large MTU is not supported over NBT (tcp port 139).
Default:
smb2 max read
8388608
smb2 max trans (G)
This option specifies the protocol value that
smbd
(8)
will return to a client, informing the client of the largest
size of buffer that may be used in querying file meta-data via QUERY_INFO and related SMB2 calls.
The maximum is 8388608 bytes (8MiB), which is the same as a Windows Server 2012 r2.
Please note that the default is 8MiB, but it's limit is based on the
smb2 dialect (64KiB for SMB == 2.0, 1MiB for SMB >= 2.1 with LargeMTU).
Large MTU is not supported over NBT (tcp port 139).
Default:
smb2 max trans
8388608
smb2 max write (G)
This option specifies the protocol value that
smbd
(8)
will return to a client, informing the client of the largest
size that may be sent to the server by a single SMB2 write call.
The maximum is 8388608 bytes (8MiB), which is the same as a Windows Server 2012 r2.
Please note that the default is 8MiB, but it's limit is based on the
smb2 dialect (64KiB for SMB == 2.0, 8MiB for SMB => 2.1 with LargeMTU).
Large MTU is not supported over NBT (tcp port 139).
Default:
smb2 max write
8388608
smb3 directory leases (G)
This is an enumerated type that controls
smbd
whether SMB3 directory leases are
enabled. Directory Leasing is an SMB3-only feature which allows
clients to cache directories.
Possible values for
smb3 directory leases
are
yes
no
and
auto
auto
being the
default.
When set to
auto
, the effective value depends on the
option
clustering
. If
clustering
is enabled,
smb3 directory leases
are disabled and the other way around.
smb3 directory leases
are only available
with
smb2 leases = yes
oplocks = yes
and
kernel oplocks = no
Enabling
smb3 directory leases
implicitly enables
strict rename
Default:
smb3 directory leases
auto
smb3 share cap:CONTINUOUS AVAILABILITY (S)
The SMB3 protocol introduced the SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY
flag. It means clients can have different expectations from the
server (or cluster of servers).
Note: this option only applies to disk shares.
In a ctdb cluster shares are continuously available,
but windows clients mix this with the global persistent
handles support.
Persistent handles are requested if
SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY is present
even without SMB2_CAP_PERSISTENT_HANDLES.
And SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY is
required for SMB2_SHARE_CAP_CLUSTER to have
an effect.
So we better don't announce this by default
until we support persistent handles.
The
smb3 share cap:CONTINUOUS AVAILABILITY
option
can be used to force the announcement of SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY.
Warning: only use this if you know what you are doing!
smb3 share cap:CONTINUOUS AVAILABILITY = yes
No default
smb3 share cap:SCALE OUT (S)
The SMB3 protocol introduced the SMB2_SHARE_CAP_SCALEOUT
flag. It means clients can have different expectations from
cluster of multiple servers and alters the retry/reconnect
behavior.
Note: this option only applies to disk shares.
In a ctdb cluster we have multiple active nodes,
so we announce SMB2_SHARE_CAP_SCALEOUT in a cluster.
The
smb3 share cap:SCALE OUT
option
can be used to disable the announcement of SMB2_SHARE_CAP_SCALEOUT,
even if
clustering
is yes.
clustering = yes
smb3 share cap: SCALE OUT = no
No default
smb3 share cap:CLUSTER (S)
The SMB3 protocol introduced the SMB2_SHARE_CAP_CLUSTER
flag. It means clients can expect that all cluster nodes
provide a witness service in order to use the [MS-SWN]
protocol to monitor the server cluster.
Note: this option only applies to disk shares.
rpcd_witness is only active if
samba-dcerpcd
(8)
is not started as on demand helper and only in a ctdb cluster.
So we announce SMB2_SHARE_CAP_CLUSTER only if
clustering
is yes and
rpc start on demand helpers
is no.
The
smb3 share cap:SCALE OUT
option
can be used to control the announcement of SMB2_SHARE_CAP_CLUSTER
independent of
clustering
and
rpc start on demand helpers
Example to disable the announcement of SMB2_SHARE_CAP_CLUSTER:
clustering = yes
rpc start on demand helpers = no
smb3 share cap: CLUSTER = no
Example to force the announcement of SMB2_SHARE_CAP_CLUSTER:
smb3 share cap: CLUSTER = yes
Example to let Windows clients use the witness service,
see
smb3 share cap:CONTINUOUS AVAILABILITY
option
and USE AT YOUR OWN RISK!:
clustering = yes
rpc start on demand helpers = no
# This is the default with the above:
# smb3 share cap: CLUSTER = yes
# Use at you own risk!
smb3 share cap: CONTINUOUS AVAILABILITY = yes
No default
smb3 share cap:ASYMMETRIC (S)
The SMB3_02 protocol introduced the SMB2_SHARE_CAP_ASYMMETRIC
flag. It means clients alters its behavior and uses
isolated transport connections and witness registrations for
the share. It means a client may connect to different
cluster nodes for individual shares and
net witness share-move
can be used
to control the node usage.
Note: this option only applies to disk shares.
Shares in a ctdb cluster are symmetric by design,
so we don't announce SMB2_SHARE_CAP_ASYMMETRIC by default.
The
smb3 share cap:ASYMMETRIC
option
can be used to force the announcement of SMB2_SHARE_CAP_ASYMMETRIC.
Example to force the announcement of SMB2_SHARE_CAP_ASYMMETRIC:
smb3 share cap: ASYMMETRIC = yes
Example to let Windows clients use the witness service,
see
smb3 share cap:CONTINUOUS AVAILABILITY
option
and USE AT YOUR OWN RISK!:
clustering = yes
rpc start on demand helpers = no
# This is the default with the above:
# smb3 share cap: CLUSTER = yes
# Use at you own risk!
smb3 share cap: CONTINUOUS AVAILABILITY = yes
smb3 share cap: ASYMMETRIC = yes
No default
smb3 unix extensions (S)
Support for SMB 3.1.1 Unix Extensions.
Default:
smb3 unix extensions
yes
smbd async dosmode (S)
This parameter control whether the fileserver will use sync or async
methods for fetching the DOS attributes when doing a directory listing. By default sync methods will be
used.
Default:
smbd async dosmode
no
smbd getinfo ask sharemode (S)
This parameter allows disabling fetching file write time from the open
file handle database locking.tdb when a client requests file or
directory metadata. It's a performance optimisation at the expense of
protocol correctness.
Default:
smbd getinfo ask sharemode
yes
smbd max async dosmode (S)
This parameter controls how many async operations to fetch the DOS
attributes the fileserver will queue when doing directory listings.
Default:
smbd max async dosmode
aio max threads * 2
smbd max xattr size (S)
This parameter controls the maximum size of extended attributes
that may be written to the server as EAs or as alternate data
streams if vfs_streams_xattr is enabled. The maximum size of
extended attributes depends on the Samba server's operating system
and the underlying filesystem. The Linux VFS currently sets an
upper boundary of 64 KiB per extended attribute. FreeBSD does not
set a practical upper limit, but since pread() and pwrite() are not
possible via the extattr on FreeBSD, it is not recommended to
increase this value above a few MiB.

If a client attempts to write an overly-large alternate datastream,
the Samba server will return STATUS_FILESYSTEM_LIMITATION.
If this error is encountered, users may try increasing the maximum
size supported for xattr writes. If this is not possible, and
writes are from a MacOS client and to an AFP_Resource extended
attribute, the user may enable the vfs_fruit module and configure
to allow stream writes for AFP_Resource to an alternative storage
location. See vfs_fruit documentation for further details.
Default:
smbd max xattr size
65536
smbd profiling share (S)
This parameter allows the administrator to enable per-share
profiling support. When enabled, profile counters may be collected
with per-share granularity a specific shares. Takes affect only
when global option
smbd profiling level
is enabled.
Default:
smbd profiling share
no
smbd profiling level (G)
This parameter allows the administrator to enable profiling support.
Possible values are
off
count
and
on
Default:
smbd profiling level
off
Example:
smbd profiling level
on
smbd search ask sharemode (S)
This parameter allows disabling fetching file write time from the open
file handle database locking.tdb. It's a performance optimisation at
the expense of protocol correctness.
Default:
smbd search ask sharemode
yes
smb encrypt (S)
This is a synonym for
server smb encrypt
Default:
smb encrypt
default
smb passwd file (G)
This option sets the path to the encrypted smbpasswd file. By
default the path to the smbpasswd file is compiled into Samba.
An example of use is:
smb passwd file = /etc/samba/smbpasswd
Default:
smb passwd file
${prefix}/private/smbpasswd
socket options (G)
Warning
Modern server operating systems are tuned for high
network performance in the majority of situations; when you set socket
options you are overriding those settings. Linux in particular has an
auto-tuning mechanism for buffer sizes that will be disabled if you
specify a socket buffer size. This can potentially cripple your
TCP/IP stack.
Getting the socket options correct can make a big difference to
your performance, but getting them wrong can degrade it by just as
much. As with any other low level setting, if you must make changes
to it, make small changes and
test
the effect
before making any large changes.
This option allows you to set socket options
to be used when talking with the client.
Socket options are controls on the networking layer
of the operating systems which allow the connection to be
tuned.
This option will typically be used to tune your Samba server
for optimal performance for your local network. There is no way
that Samba can know what the optimal parameters are for your net,
so you must experiment and choose them yourself. We strongly
suggest you read the appropriate documentation for your operating
system first (perhaps
man
setsockopt
will help).
You may find that on some systems Samba will say
"Unknown socket option" when you supply an option. This means you
either incorrectly typed it or you need to add an include file
to includes.h for your OS. If the latter is the case please
send the patch to
samba-technical@lists.samba.org
Any of the supported socket options may be combined
in any way you like, as long as your OS allows it.
This is the list of socket options currently settable
using this option:
SO_KEEPALIVE
SO_REUSEADDR
SO_BROADCAST
TCP_NODELAY
TCP_KEEPCNT *
TCP_KEEPIDLE *
TCP_KEEPINTVL *
IPTOS_LOWDELAY
IPTOS_THROUGHPUT
SO_REUSEPORT
SO_SNDBUF *
SO_RCVBUF *
SO_SNDLOWAT *
SO_RCVLOWAT *
SO_SNDTIMEO *
SO_RCVTIMEO *
TCP_FASTACK *
TCP_QUICKACK
TCP_NODELAYACK
TCP_KEEPALIVE_THRESHOLD *
TCP_KEEPALIVE_ABORT_THRESHOLD *
TCP_DEFER_ACCEPT *
TCP_USER_TIMEOUT *
Those marked with a
'*'
take an integer
argument. The others can optionally take a 1 or 0 argument to enable
or disable the option, by default they will be enabled if you
don't specify 1 or 0.
To specify an argument use the syntax SOME_OPTION = VALUE
for example
SO_SNDBUF = 8192
. Note that you must
not have any spaces before or after the = sign.
If you are on a local network then a sensible option
might be:
socket options = IPTOS_LOWDELAY
If you have a local network then you could try:
socket options = IPTOS_LOWDELAY TCP_NODELAY
If you are on a wide area network then perhaps try
setting IPTOS_THROUGHPUT.
Note that several of the options may cause your Samba
server to fail completely. Use these options with caution!
Default:
socket options
TCP_NODELAY
Example:
socket options
IPTOS_LOWDELAY
spn update command (G)
This option sets the command that for updating
servicePrincipalName names from
spn_update_list
Default:
spn update command
${prefix}/sbin/samba_spnupdate
Example:
spn update command
/usr/local/sbin/spnupdate
spoolss: architecture (G)
Windows spoolss print clients only allow association of server-side drivers
with printers when the driver architecture matches the advertised print server
architecture. Samba's spoolss print server architecture can be changed using
this parameter.
Default:
spoolss: architecture
Windows x64
Example:
spoolss: architecture
Windows NT x86
spoolss: os_major (G)
Windows might require a new os version number. This option allows
to modify the build number. The complete default version number is:
5.0.2195 (Windows 2000). The example is 6.1.7601 (Windows 2008 R2).
Default:
spoolss: os_major
Example:
spoolss: os_major
spoolss: os_minor (G)
Windows might require a new os version number. This option allows
to modify the build number. The complete default version number is:
5.0.2195 (Windows 2000). The example is 6.1.7601 (Windows 2008 R2).
Default:
spoolss: os_minor
Example:
spoolss: os_minor
spoolss: os_build (G)
Windows might require a new os version number. This option allows
to modify the build number. The complete default version number is:
5.0.2195 (Windows 2000). The example is 6.1.7601 (Windows 2008 R2).
Default:
spoolss: os_build
2195
Example:
spoolss: os_build
7601
spoolss_client: os_major (G)
Windows might require a new os version number. This option allows
to modify the build number. The complete default version number is:
6.1.7007 (Windows 7 and Windows Server 2008 R2).
Default:
spoolss_client: os_major
spoolss_client: os_minor (G)
Windows might require a new os version number. This option allows
to modify the build number. The complete default version number is:
6.1.7007 (Windows 7 and Windows Server 2008 R2).
Default:
spoolss_client: os_minor
spoolss_client: os_build (G)
Windows might require a new os version number. This option allows
to modify the build number. The complete default version number is:
6.1.7007 (Windows 7 and Windows Server 2008 R2).
Default:
spoolss_client: os_build
7007
spotlight backend (S)
Spotlight search backend. Available backends:
noindex
a backend that returns no results.
tracker
Gnome Tracker.
elasticsearch
a backend that uses JSON and REST over HTTP(s) to query an
Elasticsearch server.
Default:
spotlight backend
noindex
spotlight (S)
This parameter controls whether Samba allows Spotlight
queries on a share. For controlling indexing of filesystems
you also have to use Tracker's own configuration system.
Spotlight has several prerequisites:
Samba must be configured and built with Spotlight support.
Tracker integration must be setup and the
share must be indexed by Tracker.
For a detailed set of instructions please see
Default:
spotlight
no
stat cache (G)
This parameter determines if
smbd
(8)
will use a cache in order to
speed up case insensitive name mappings. You should never need
to change this parameter.
Default:
stat cache
yes
state directory (G)
Usually, most of the TDB files are stored in the
lock directory
. Since
Samba 3.4.0, it is possible to differentiate between TDB files
with persistent data and TDB files with non-persistent data using
the
state directory
and the
cache directory
options.
This option specifies the directory where TDB files containing
important persistent data will be stored.
Default:
state directory
${prefix}/var/locks
Example:
state directory
/var/run/samba/locks/state
store dos attributes (S)
If this parameter is set Samba attempts to first read DOS attributes (SYSTEM, HIDDEN, ARCHIVE or
READ-ONLY) from a filesystem extended attribute, before mapping DOS attributes to UNIX permission bits (such
as occurs with
map hidden
and
map readonly
). When set, DOS
attributes will be stored onto an extended attribute in the UNIX filesystem, associated with the file or
directory. When this parameter is set it will override the parameters
map hidden
map system
map archive
and
map readonly
and they will behave as if they were set to off. This parameter writes the DOS attributes as a string into the extended
attribute named "user.DOSATTRIB". This extended attribute is explicitly hidden from smbd clients requesting an
EA list. On Linux the filesystem must have been mounted with the mount option user_xattr in order for
extended attributes to work, also extended attributes must be compiled into the Linux kernel.

In Samba 3.5.0 and above the "user.DOSATTRIB" extended attribute has been extended to store
the create time for a file as well as the DOS attributes. This is done in a backwards compatible
way so files created by Samba 3.5.0 and above can still have the DOS attribute read from this
extended attribute by earlier versions of Samba, but they will not be able to read the create
time stored there. Storing the create time separately from the normal filesystem meta-data
allows Samba to faithfully reproduce NTFS semantics on top of a POSIX filesystem.

The default has changed to yes in Samba release 4.9.0 and above to allow better Windows
fileserver compatibility in a default install.
Default:
store dos attributes
yes
strict allocate (S)
This is a boolean that controls the handling of
disk space allocation in the server. When this is set to
yes
the server will change from UNIX behaviour of not committing real
disk storage blocks when a file is extended to the Windows behaviour
of actually forcing the disk system to allocate real storage blocks
when a file is created or extended to be a given size. In UNIX
terminology this means that Samba will stop creating sparse files.
This option is really designed for file systems that support
fast allocation of large numbers of blocks such as extent-based file systems.
On file systems that don't support extents (most notably ext3) this can
make Samba slower. When you work with large files over >100MB on file
systems without extents you may even run into problems with clients
running into timeouts.
When you have an extent based filesystem it's likely that we can make
use of unwritten extents which allows Samba to allocate even large amounts
of space very fast and you will not see any timeout problems caused by
strict allocate. With strict allocate in use you will also get much better
out of quota messages in case you use quotas. Another advantage of
activating this setting is that it will help to reduce file
fragmentation.
To give you an idea on which filesystems this setting might currently
be a good option for you: XFS, ext4, btrfs, ocfs2 on Linux and JFS2 on
AIX support unwritten extents. On Filesystems that do not support it,
preallocation is probably an expensive operation where you will see reduced
performance and risk to let clients run into timeouts when creating large
files. Examples are ext3, ZFS, HFS+ and most others, so be aware if you
activate this setting on those filesystems.
Default:
strict allocate
no
strict locking (S)
This is an enumerated type that controls the handling of file locking in the server. When this is set to
yes
the server will check every read and write access for file locks, and deny access if locks exist. This can be slow on
some systems.
When strict locking is set to Auto (the default), the server performs file lock checks only on non-oplocked files.
As most Windows redirectors perform file locking checks locally on oplocked files this is a good trade off for
improved performance.
When strict locking is disabled, the server performs file lock checks only when the client explicitly asks for them.
Well-behaved clients always ask for lock checks when it is important. So in the vast majority of cases,
strict locking = Auto
or
strict locking = no
is acceptable.
Default:
strict locking
Auto
strict rename (S)
By default a Windows SMB server prevents directory
renames when there are open file or directory handles below
it in the filesystem hierarchy. Historically Samba has always
allowed this as POSIX filesystem semantics require it.
This boolean parameter allows Samba to match the Windows
behavior. Setting this to "yes" is a very expensive change,
as it forces Samba to travers the entire open file handle
database on every directory rename request. In a clustered
Samba system the cost is even greater than the non-clustered
case.
When set to "no" smbd only checks the local process
the client is attached to for open files below a directory
being renamed, instead of checking for open files across all
smbd processes.
Because of the expense in fully searching the database,
the default is "no", and it is recommended to be left that way
unless a specific Windows application requires it to be changed.
If the client has requested UNIX extensions (POSIX
pathnames) then renames are always allowed and this parameter
has no effect.
Enabling
smb3 directory leases
implicitly
enables
strict rename
Default:
strict rename
no
strict sync (S)
This parameter controls whether Samba honors a request
from an SMB client to ensure any outstanding operating system
buffer contents held in memory are safely written onto stable
storage on disk. If set to
yes
, which is
the default, then Windows applications can force the smbd server
to synchronize unwritten data onto the disk. If set to
no
then smbd will ignore client
requests to synchronize unwritten data onto stable storage on
disk.
In Samba 4.7.0, the default for this parameter changed from
no
to
yes
to better
match the expectations of SMB2/3 clients and improve application
safety when running against smbd.
The flush request from SMB2/3 clients is handled
asynchronously inside smbd, so leaving the parameter as the default
value of
yes
does not block the processing of
other requests to the smbd process.
Legacy Windows applications (such as the Windows 98 explorer
shell) seemed to confuse writing buffer contents to the operating
system with synchronously writing outstanding data onto stable storage
on disk. Changing this parameter to
no
means that
smbd
(8)
will ignore the Windows
applications request to synchronize unwritten data onto disk. Only
consider changing this if smbd is serving obsolete SMB1 Windows clients
prior to Windows XP (Windows 98 and below). There should be no need to
change this setting for normal operations.
Default:
strict sync
yes
svcctl list (G)
This option defines a list of init scripts that smbd
will use for starting and stopping Unix services via the Win32
ServiceControl API. This allows Windows administrators to
utilize the MS Management Console plug-ins to manage a
Unix server running Samba.
The administrator must create a directory
name
svcctl
in Samba's $(libdir)
and create symbolic links to the init scripts in
/etc/init.d/
. The name of the links
must match the names given as part of the
svcctl list
Default:
svcctl list
Example:
svcctl list
cups postfix portmap httpd
sync always (S)
This is a boolean parameter that controls
whether writes will always be written to stable storage before
the write call returns. If this is
no
then the server will be
guided by the client's request in each write call (clients can
set a bit indicating that a particular write should be synchronous).
If this is
yes
then every write will be followed by a
fsync()
call to ensure the data is written to disk. Note that
the
strict sync
parameter must be set to
yes
in order for this parameter to have
any effect.
Default:
sync always
no
sync machine password script (G)
This is the full pathname to a script that will be run by
winbindd
(8)
when a machine account password is updated.
If keytabs should be generated in clustered environments it is recommended to update them on all nodes.
You can set the config option to ${prefix}/share/ctdb/scripts/winbind_ctdb_updatekeytab.sh in clustering case.
It is also needed to activate the
46.update-keytabs.script
in ctdb,
it re-creates the keytab during the ctdb recovered event:
onnode all ctdb event script enable legacy 46.update-keytabs.script
Default:
sync machine password script
Example:
sync machine password script
${prefix}/share/ctdb/scripts/winbind_ctdb_updatekeytab.sh
sync machine password to keytab (G)
This option allows you to describe what keytabs and how should be updated when
machine account is changed via one of these commands
wbinfo --change-secret
rpcclient --machine-pass -c change_trust_pw
net rpc changetrustpw
net ads changetrustpw
or by winbindd doing regular updates (see
machine password timeout
The option takes a list of keytab strings to describe how to synchronize
content of those keytabs or a single 'disabled' value to disable the
synchronization.

Each string has this form:
absolute_path_to_keytab:spn_spec[:spn_spec]*[:sync_etypes][:sync_kvno][:netbios_aliases][:additional_dns_hostnames][:machine_password]
spn_spec can be specified multiple times (separated using ':') and each spn_spec can have exactly one of these forms:
account_name
sync_account_name
sync_upn
sync_spns
spn_prefixes=value1[,value2[...]]
spns=value1[,value2[...]]
Every keytab contains principals according the specification below:
account_name - COMPUTER$@REALM
sync_account_name - uses attribute "sAMAccountName" from AD
sync_upn - uses attribute "userPrincipalName" (if exists in AD)
sync_spns - uses attribute "servicePrincipalName" (if exists in AD)
spn_prefixes - creates these two principals from each prefix. e.g.:
prefix/
netbios name
@REALM
prefix/
dns hostname
@REALM
with :netbios_aliases for each netbiosalias in
netbios aliases
prefix/netbiosalias@REALM
prefix/netbiosalias.dnsdomain@REALM
with :additional_dns_hostnames for each additionaldnshostname in
additional dns hostnames
prefix/additionaldnshostname@REALM
- 'host' principal should be created using specifier spn_prefixes
spns - creates only the principals defined in the list
'account_name' and 'sync_account_name' are the same, just the source differs (secrets.tdb vs. AD).
Options:
sync_etypes - attribute "msDS-SupportedEncryptionTypes" is read from AD and is used to find the highest common enc type for AD and KRB5 lib.
sync_kvno - attribute "msDS-KeyVersionNumber" from AD is used to set KVNO. If this option is missing, KVNO is set to -1.
netbios_aliases - evaluated only for spn_prefixes (see details above).
additional_dns_hostnames - evaluated only for spn_prefixes (see details above).
machine_password - mandatory, if missing the entry is ignored. For future use.
Example:
"/path/to/keytab0:account_name:machine_password",
"/path/to/keytab1:account_name:sync_etypes:sync_kvno:machine_password",
"/path/to/keytab2:sync_spns:machine_password",
"/path/to/keytab3:sync_spns:sync_kvno:machine_password",
"/path/to/keytab4:spn_prefixes=imap,smtp:machine_password",
"/path/to/keytab5:spn_prefixes=imap,smtp:netbios_aliases:additional_dns_hostnames:sync_kvno:machine_password",
"/path/to/keytab6:spns=wurst/brot@REALM:machine_password",
"/path/to/keytab7:spns=wurst/brot@REALM,wurst2/brot@REALM:sync_kvno:machine_password",
"/path/to/keytab8:sync_account_name:sync_upn:sync_spns:spn_prefixes=host,cifs,http:spns=wurst/brot@REALM:sync_kvno:machine_password"
If sync_etypes or sync_kvno or sync_spns is present then winbind connects to DC. For "offline domain join" it might be useful not to use these options.
If no value is present and
kerberos method
is different from
'secrets only', the behavior differs between winbind and net utility:
winbind
uses value
/path/to/keytab:host:account_name:sync_spns:sync_kvno:machine_password
where the path to the keytab is obtained either from the krb5 library or from
dedicated keytab file
net changesecretpw -f
command uses the default 'disabled' value.
No other
net
subcommands use the 'disabled' value.
If a single value 'disabled' is present, the synchronization process is
disabled. This is required for FreeIPA domain member setup where keytab
synchronization uses a protocol not implemented by Samba.
Suggested configuration is together with
kerberos method
set to the default value 'secrets only'.
In clustered environments it is recommended to set
sync machine password script
to update the machine password on all nodes.
No default
syslog only (G)
If this parameter is set then Samba debug messages are logged into the system
syslog only, and not to the debug log files. There still will be some
logging to log.[sn]mbd even if
syslog only
is enabled.
The
logging
parameter should be used
instead. When
logging
is set, it
overrides the
syslog only
parameter.
Default:
syslog only
no
syslog (G)
This parameter maps how Samba debug messages are logged onto the system syslog logging levels.
Samba debug level zero maps onto syslog
LOG_ERR
, debug level one maps onto
LOG_WARNING
, debug level two maps onto
LOG_NOTICE
debug level three maps onto LOG_INFO. All higher levels are mapped to
LOG_DEBUG
This parameter sets the threshold for sending messages to syslog. Only messages with debug
level less than this value will be sent to syslog. There still will be some
logging to log.[sn]mbd even if
syslog only
is enabled.
The
logging
parameter should be used
instead. When
logging
is set, it
overrides the
syslog
parameter.
Default:
syslog
template homedir (G)
When filling out the user information for a Windows NT
user, the
winbindd
(8)
daemon uses this
parameter to fill in the home directory for that user. If the
string
%D
is present it
is substituted with the user's Windows NT domain name. If the
string
%U
is present it
is substituted with the user's Windows NT user name.
Default:
template homedir
/home/%D/%U
template shell (G)
When filling out the user information for a Windows NT
user, the
winbindd
(8)
daemon uses this
parameter to fill in the login shell for that user.
Default:
template shell
/bin/false
time server (G)
This parameter determines if
nmbd
(8)
advertises itself as a time server to Windows
clients.
Default:
time server
no
debug timestamp
This parameter is a synonym for
timestamp logs
timestamp logs (G)
Samba debug log messages are timestamped by default. If you are running at a high
debug level
these timestamps can be distracting. This
boolean parameter allows timestamping to be turned off.
Default:
timestamp logs
yes
tls ca directories (G)
This option can be set to a list of directories with files (in PEM format)
containing CA certificates of root CAs to trust to sign
certificates or intermediate CA certificates.
No default
tls cafile (G)
This option can be set to a file (PEM format)
containing CA certificates of root CAs to trust to sign
certificates or intermediate CA certificates.
This path is relative to
private dir
if the path
does not start with a /.
Default:
tls cafile
tls/ca.pem
tls certfile (G)
This option can be set to a file (PEM format)
containing the RSA certificate to be used as TLS server certificate.
If required it can also contain additional intermediate certificates to be send along during the TLS handshake.
This path is relative to
private dir
if the path
does not start with a /.
Default:
tls certfile
tls/cert.pem
tls crlfile (G)
This option can be set to a file containing a certificate
revocation list (CRL).
This path is relative to
private dir
if the path
does not start with a /.
Default:
tls crlfile
tls dh params file (G)
This option can be set to a file with Diffie-Hellman parameters
which will be used with DH ciphers.
This path is relative to
private dir
if the path
does not start with a /.
Default:
tls dh params file
tls enabled (G)
If this option is set to
yes
, then Samba
will use TLS when possible in communication.
Default:
tls enabled
yes
tls keyfile (G)
This option can be set to a file (PEM format)
containing the RSA private key. This file must be accessible without
a pass-phrase, i.e. it must not be encrypted.
This path is relative to
private dir
if the path
does not start with a /.
Default:
tls keyfile
tls/key.pem
tls priority (G)
This option can be set to a string describing the TLS protocols
to be supported in the parts of Samba that use GnuTLS, specifically
the AD DC.
The string is appended to the default priority list of GnuTLS.
The valid options are described in the
GNUTLS
Priority-Strings documentation at http://gnutls.org/manual/html_node/Priority-Strings.html
The SSL3.0 protocol will be disabled.
Default:
tls priority
NORMAL:-VERS-SSL3.0
tls trust system cas (G)
With this option the system's default trusted CAs are
used to trust SSL/TLS connections.
Please use this with care, as it really means
trusting all CAs installed on the system!
Default:
tls trust system cas
no
tls verify peer (G)
This controls if and how strict the client will verify the peer's certificate and name.
Possible values are (in increasing order):
no_check
ca_only
ca_and_name_if_available
ca_and_name
and
as_strict_as_possible
When set to
no_check
the certificate is not verified at
all, which allows trivial man in the middle attacks.
When set to
ca_only
the certificate is verified to
be signed from a ca specified in the
tls ca file
option.
As alternative
tls ca directories
or
tls trust system cas
can be used.
Providing at least one valid CA certificate is required.
The certificate lifetime is also verified. If the
tls crl file
option is configured, the certificate is also verified against the ca crl.
When set to
ca_and_name_if_available
all checks from
ca_only
are performed. In addition, the peer hostname is verified
against the certificate's name, if it is provided by the application layer and
not given as an ip address string.
When set to
ca_and_name
all checks from
ca_and_name_if_available
are performed.
In addition the peer hostname needs to be provided and even an ip
address is checked against the certificate's name.
When set to
as_strict_as_possible
all checks from
ca_and_name
are performed. In addition the
tls crl file
needs to be configured.
Future versions of Samba may implement additional checks.
Default:
tls verify peer
as_strict_as_possible
unicode (G)
Specifies whether the server and client should support unicode.
If this option is set to false, the use of ASCII will be forced.
Default:
unicode
yes
unix charset (G)
Specifies the charset the unix machine
Samba runs on uses. Samba needs to know this in order to be able to
convert text to the charsets other SMB clients use.
This is also the charset Samba will use when specifying arguments
to scripts that it invokes.
Default:
unix charset
UTF-8
Example:
unix charset
ASCII
unix password sync (G)
This boolean parameter controls whether Samba
attempts to synchronize the UNIX password with the SMB password
when the encrypted SMB password in the smbpasswd file is changed.
If this is set to
yes
the program specified in the
passwd
program
parameter is called
AS ROOT
to allow the new UNIX password to be set without access to the
old UNIX password (as the SMB password change code has no
access to the old password cleartext, only the new).
This option has no effect if
samba
is running as an active directory domain controller, in that case have a
look at the
password hash gpg key ids
option and the
samba-tool user syncpasswords
command.
Default:
unix password sync
no
use client driver (S)
This parameter applies only to Windows NT/2000
clients. It has no effect on Windows 95/98/ME clients. When
serving a printer to Windows NT/2000 clients without first installing
a valid printer driver on the Samba host, the client will be required
to install a local printer driver. From this point on, the client
will treat the print as a local printer and not a network printer
connection. This is much the same behavior that will occur
when
disable spoolss = yes
The differentiating factor is that under normal
circumstances, the NT/2000 client will attempt to open the network
printer using MS-RPC. The problem is that because the client
considers the printer to be local, it will attempt to issue the
OpenPrinterEx() call requesting access rights associated with the
logged on user. If the user possesses local administrator rights but
not root privilege on the Samba host (often the case), the
OpenPrinterEx() call will fail. The result is that the client will
now display an "Access Denied; Unable to connect" message
in the printer queue window (even though jobs may successfully be
printed).
If this parameter is enabled for a printer, then any attempt
to open the printer with the PRINTER_ACCESS_ADMINISTER right is mapped
to PRINTER_ACCESS_USE instead. Thus allowing the OpenPrinterEx()
call to succeed.
This parameter MUST not be enabled
on a print share which has valid print driver installed on the Samba
server.
Default:
use client driver
no
use mmap (G)
This global parameter determines if the tdb internals of Samba can
depend on mmap working correctly on the running system. Samba requires a coherent
mmap/read-write system memory cache. Currently only OpenBSD and HPUX do not have such a
coherent cache, and on those platforms this parameter is overridden internally
to be effectively
no
. On all systems this parameter should be left alone. This
parameter is provided to help the Samba developers track down problems with
the tdb internal code.
Default:
use mmap
yes
username level (G)
This option helps Samba to try and 'guess' at
the real UNIX username, as many DOS clients send an all-uppercase
username. By default Samba tries all lowercase, followed by the
username with the first letter capitalized, and fails if the
username is not found on the UNIX machine.
If this parameter is set to non-zero the behavior changes.
This parameter is a number that specifies the number of uppercase
combinations to try while trying to determine the UNIX user name. The
higher the number the more combinations will be tried, but the slower
the discovery of usernames will be. Use this parameter when you have
strange usernames on your UNIX machine, such as
AstrangeUser
This parameter is needed only on UNIX systems that have case
sensitive usernames.
Default:
username level
Example:
username level
username map cache time (G)
Mapping usernames with the
username map
or
username map script
features of Samba can be relatively expensive.
During login of a user, the mapping is done several times.
In particular, calling the
username map script
can slow down logins if external databases have to be queried from
the script being called.
The parameter
username map cache time
controls a mapping cache. It specifies the number of seconds a
mapping from the username map file or script is to be efficiently cached.
The default of 0 means no caching is done.
Default:
username map cache time
Example:
username map cache time
60
username map script (G)
This script is a mutually exclusive alternative to the
username map
parameter. This parameter
specifies an external program or script that must accept a single
command line option (the username transmitted in the authentication
request) and return a line on standard output (the name to which
the account should mapped). In this way, it is possible to store
username map tables in an LDAP directory services.
Default:
username map script
Example:
username map script
/etc/samba/scripts/mapusers.sh
username map (G)
This option allows you to specify a file containing a mapping of usernames from the clients to the server.
This can be used for several purposes. The most common is to map usernames that users use on DOS or Windows
machines to those that the UNIX box uses. The other is to map multiple users to a single username so that they
can more easily share files.
Please note that for user mode security, the username map is applied prior to validating the user
credentials. Domain member servers (domain or ads) apply the username map after the user has been
successfully authenticated by the domain controller and require fully qualified entries in the map table (e.g.
biddle =
DOMAIN\foo
).
The map file is parsed line by line. Each line should contain a single UNIX username on the left then a '='
followed by a list of usernames on the right. The list of usernames on the right may contain names of the form
@group in which case they will match any UNIX username in that group. The special client name '*' is a
wildcard and matches any name. Each line of the map file may be up to 1023 characters long.
The file is processed on each line by taking the supplied username and comparing it with each username on the
right hand side of the '=' signs. If the supplied name matches any of the names on the right hand side then it
is replaced with the name on the left. Processing then continues with the next line.
If any line begins with a '#' or a ';' then it is ignored.
If any line begins with an '!' then the processing will stop after that line if a mapping was done by the
line. Otherwise mapping continues with every line being processed. Using '!' is most useful when you have a
wildcard mapping line later in the file.
For example to map from the name
admin
or
administrator
to the UNIX
name
root
you would use:
root = admin administrator
Or to map anyone in the UNIX group
system
to the UNIX name
sys
you would use:
sys = @system
You can have as many mappings as you like in a username map file.
If your system supports the NIS NETGROUP option then the netgroup database is checked before the
/etc/group
database for matching groups.
You can map Windows usernames that have spaces in them by using double quotes around the name. For example:
tridge = "Andrew Tridgell"
would map the windows username "Andrew Tridgell" to the unix username "tridge".
The following example would map mary and fred to the unix user sys, and map the rest to guest. Note the use of the
'!' to tell Samba to stop processing if it gets a match on that line:
!sys = mary fred
guest = *
Note that the remapping is applied to all occurrences of usernames. Thus if you connect to \\server\fred and
fred
is remapped to
mary
then you will actually be connecting to
\\server\mary and will need to supply a password suitable for
mary
not
fred
. The only exception to this is the
username passed to a Domain Controller (if you have one). The DC will receive whatever username the client
supplies without modification.
Also note that no reverse mapping is done. The main effect this has is with printing. Users who have been
mapped may have trouble deleting print jobs as PrintManager under WfWg will think they don't own the print
job.
Samba versions prior to 3.0.8 would only support reading the fully qualified username
(e.g.:
DOMAIN\user
) from
the username map when performing a kerberos login from a client. However, when looking up a map entry for a
user authenticated by NTLM[SSP], only the login name would be used for matches. This resulted in inconsistent
behavior sometimes even on the same server.
The following functionality is obeyed in version 3.0.8 and later:
When performing local authentication, the username map is applied to the login name before attempting to authenticate
the connection.
When relying upon a external domain controller for validating authentication requests, smbd will apply the username map
to the fully qualified username (i.e.
DOMAIN\user
) only after the user has been successfully authenticated.
An example of use is:
username map = /usr/local/samba/lib/users.map
Default:
username map
# no username map
usershare allow guests (G)
This parameter controls whether user defined shares are allowed
to be accessed by non-authenticated users or not. It is the equivalent
of allowing people who can create a share the option of setting
guest ok = yes
in a share
definition. Due to its security sensitive nature, the default
is set to off.
Default:
usershare allow guests
no
usershare max shares (G)
This parameter specifies the number of user defined shares
that are allowed to be created by users belonging to the group owning the
usershare directory. If set to zero (the default) user defined shares are ignored.
Default:
usershare max shares
usershare owner only (G)
This parameter controls whether the pathname exported by
a user defined shares must be owned by the user creating the
user defined share or not. If set to True (the default) then
smbd checks that the directory path being shared is owned by
the user who owns the usershare file defining this share and
refuses to create the share if not. If set to False then no
such check is performed and any directory path may be exported
regardless of who owns it.
Default:
usershare owner only
yes
usershare path (G)
This parameter specifies the absolute path of the directory on the
filesystem used to store the user defined share definition files.
This directory must be owned by root, and have no access for
other, and be writable only by the group owner. In addition the
"sticky" bit must also be set, restricting rename and delete to
owners of a file (in the same way the /tmp directory is usually configured).
Members of the group owner of this directory are the users allowed to create
usershares.
For example, a valid usershare directory might be /usr/local/samba/lib/usershares,
set up as follows.
ls -ld /usr/local/samba/lib/usershares/
drwxrwx--T 2 root power_users 4096 2006-05-05 12:27 /usr/local/samba/lib/usershares/
In this case, only members of the group "power_users" can create user defined shares.
Default:
usershare path
${prefix}/var/locks/usershares
usershare prefix allow list (G)
This parameter specifies a list of absolute pathnames
the root of which are allowed to be exported by user defined share definitions.
If the pathname to be exported doesn't start with one of the strings in this
list, the user defined share will not be allowed. This allows the Samba
administrator to restrict the directories on the system that can be
exported by user defined shares.
If there is a "usershare prefix deny list" and also a
"usershare prefix allow list" the deny list is processed
first, followed by the allow list, thus leading to the most
restrictive interpretation.
Default:
usershare prefix allow list
Example:
usershare prefix allow list
/home /data /space
usershare prefix deny list (G)
This parameter specifies a list of absolute pathnames
the root of which are NOT allowed to be exported by user defined share definitions.
If the pathname exported starts with one of the strings in this
list the user defined share will not be allowed. Any pathname not
starting with one of these strings will be allowed to be exported
as a usershare. This allows the Samba administrator to restrict the
directories on the system that can be exported by user defined shares.
If there is a "usershare prefix deny list" and also a
"usershare prefix allow list" the deny list is processed
first, followed by the allow list, thus leading to the most
restrictive interpretation.
Default:
usershare prefix deny list
Example:
usershare prefix deny list
/etc /dev /private
usershare template share (G)
User defined shares only have limited possible parameters
such as path, guest ok, etc. This parameter allows usershares to
"cloned" from an existing share. If "usershare template share"
is set to the name of an existing share, then all usershares
created have their defaults set from the parameters set on this
share.
The target share may be set to be invalid for real file
sharing by setting the parameter "-valid = False" on the template
share definition. This causes it not to be seen as a real exported
share but to be able to be used as a template for usershares.
Default:
usershare template share
Example:
usershare template share
template_share
use sendfile (S)
If this parameter is
yes
, and the
sendfile()
system call is supported by the underlying operating system, then some SMB read calls
(mainly ReadAndX and ReadRaw) will use the more efficient sendfile system call for files that
are exclusively oplocked. This may make more efficient use of the system CPU's
and cause Samba to be faster. Samba automatically turns this off for clients
that use protocol levels lower than NT LM 0.12 and when it detects a client is
Windows 9x (using sendfile from Linux will cause these clients to fail).
Default:
use sendfile
no
utmp directory (G)
This parameter is only available if Samba has
been configured and compiled with the option
--with-utmp
. It specifies a directory pathname that is
used to store the utmp or utmpx files (depending on the UNIX system) that
record user connections to a Samba server. By default this is
not set, meaning the system will use whatever utmp file the
native system is set to use (usually
/var/run/utmp
on Linux).
Default:
utmp directory
# Determined automatically
Example:
utmp directory
/var/run/utmp
utmp (G)
This boolean parameter is only available if Samba has been configured and compiled
with the option
--with-utmp
. If set to
yes
then Samba will attempt to add utmp or utmpx records
(depending on the UNIX system) whenever a connection is made to a Samba server.
Sites may use this to record the user connecting to a Samba share.
Due to the requirements of the utmp record, we are required to create a unique
identifier for the incoming user. Enabling this option creates an n^2 algorithm
to find this number. This may impede performance on large installations.
Default:
utmp
no
valid users (S)
This is a list of users that should be allowed to login to this service. Names starting with
'@', '+' and '&' are interpreted using the same rules as described in the
invalid users
parameter.
If this is empty (the default) then any user can login. If a username is in both this list
and the
invalid users
list then access is denied
for that user.
The current servicename is substituted for
%S
This is useful in the [homes] section.
Note:
When used in the [global] section this
parameter may have unwanted side effects. For example: If samba is configured as a MASTER BROWSER (see
local master
os level
domain master
preferred master
) this option
will prevent workstations from being able to browse the network.
Default:
valid users
# No valid users list (anyone can login)
Example:
valid users
greg, @pcusers
-valid (S)
This parameter indicates whether a share is
valid and thus can be used. When this parameter is set to false,
the share will be in no way visible nor accessible.
This option should not be
used by regular users but might be of help to developers.
Samba uses this option internally to mark shares as deleted.
Default:
-valid
yes
veto files (S)
This is a list of files and directories that are neither visible nor accessible. Each entry in
the list must be separated by a '/', which allows spaces to be included in the entry. '*' and '?'
can be used to specify multiple files or directories as in DOS wildcards.
veto files
can also be used as a
parametric option where NAME in
veto files : NAME =
specifies a user or group name with the same syntax as
valid users
. This parametric form can
be specified multiple times for different users or
groups. This means that "veto files : NAME" set both
in the [global] and the share section add up, whereas normally
options set in a share section overwrite the default in the
[global] section.
Each filename must be a unix path, not a DOS path and must
not
include the
unix directory separator '/'.
Note that the
case sensitive
option is applicable in vetoing files.
One feature of the veto files parameter that it is important to be aware of is Samba's behaviour when
trying to delete a directory. If a directory that is to be deleted contains nothing but veto files this
deletion will
fail
unless you also set the
delete veto files
parameter to
yes
Setting this parameter will affect the performance of Samba, as it will be forced to check all files
and directories for a match as they are scanned.
Examples of use include:
; Veto any files containing the word Security,
; any ending in .tmp, and any directory containing the
; word root.
veto files = /*Security*/*.tmp/*root*/

; Veto some files for anyone and some files for specific users and groups
veto files = /vetoforall1/
veto files : USER = /vetotoforuser/
veto files : GROUP = /vetoforgroup/
veto files : UNIVERSITY\Alumnis = /somefile.txt/
veto files : john@university.org = /anotherfile.txt/
veto files : S-1-5-21-123-456-789-1000 = /secretfile.txt/

; Veto the Apple specific files that a NetAtalk server
; creates.
veto files = /.AppleDouble/.bin/.AppleDesktop/Network Trash Folder/
Default:
veto files
# No files or directories are vetoed
veto oplock files (S)
This parameter is only valid when the
oplocks
parameter is turned on for a share. It allows the Samba administrator
to selectively turn off the granting of oplocks on selected files that
match a wildcarded list, similar to the wildcarded list used in the
veto files
parameter.
You might want to do this on files that you know will be heavily contended
for by clients. A good example of this is in the NetBench SMB benchmark
program, which causes heavy client contention for files ending in
.SEM
. To cause Samba not to grant
oplocks on these files you would use the line (either in the [global]
section or in the section for the particular NetBench share.
An example of use is:
veto oplock files = /.*SEM/
Default:
veto oplock files
# No files are vetoed for oplock grants
vfs mkdir use tmp name (S)
Creating a new directory for an SMB client is a very complex task!
It includes things like inheriting permissions from the parent directory
and storing DOS attributes.
Other clients should not see the existence of the directory that
is in progress of being created!
This option is an enumerated type that controls the usage of a temporary directory name.
When this is set to
yes
the directory name will be prefixed with '.::TMPNAME:D:$SERVERID:' (where $SERVERID is
a unique identifier for the current process).
When this option is set to Auto (the default), the server uses a temporary directory name
if, at least, one of the following options
is effectively not set to
no
inherit acls
inherit owner
inherit permissions
nt acl support
or
store dos attributes
Note on OpenBSD Auto (the default) is mapped to
no
see
A re-export of an SMB/CIFS mount might one rare case where
vfs mkdir use tmp name = no
could be useful.
In most cases
vfs mkdir use tmp name = Auto
should be kept.
Default:
vfs mkdir use tmp name
Auto
vfs object
This parameter is a synonym for
vfs objects
vfs objects (S)
This parameter specifies the backend names which
are used for Samba VFS I/O operations. By default, normal
disk I/O operations are used but these can be overloaded
with one or more VFS objects. Be aware that the definition of this
parameter will overwrite a possible previous definition of the
vfs objects parameter.
Default:
vfs objects
Example:
vfs objects
extd_audit recycle
volume serial number (S)
This allows to override the volume serial number
(a 32bit value) reported for a share.
The special value
-1
(default) stands for
a unique number that is calculated for each share.
Default:
volume serial number
-1
Example:
volume serial number
0xabcdefgh
volume (S)
This allows you to override the volume label
returned for a share. Useful for CDROMs with installation programs
that insist on a particular volume label.
Default:
volume
# the name of the share
wide links (S)
This parameter controls whether or not links
in the UNIX file system may be followed by the server. Links
that point to areas within the directory tree exported by the
server are always allowed; this parameter controls access only
to areas that are outside the directory tree being exported.
Note: Turning this parameter on when UNIX extensions are enabled
will allow UNIX clients to create symbolic links on the share that
can point to files or directories outside restricted path exported
by the share definition. This can cause access to areas outside of
the share. Due to this problem, this parameter will be automatically
disabled (with a message in the log file) if the
unix extensions
option is on.
See the parameter
allow insecure wide links
if you wish to change this coupling between the two parameters.
Default:
wide links
no
winbind cache time (G)
This parameter specifies the number of
seconds the
winbindd
(8)
daemon will cache
user and group information before querying a Windows NT server
again.
This does not apply to authentication requests, these are always
evaluated in real time unless the
winbind offline logon
option has been enabled.
Default:
winbind cache time
300
winbindd socket directory (G)
This setting controls the location of the winbind daemon's socket.
Except within automated test scripts, this should not be
altered, as the client tools (nss_winbind etc) do not honour
this parameter. Client tools must then be advised of the
altered path with the WINBINDD_SOCKET_DIR environment
variable.
Default:
winbindd socket directory
${prefix}/var/run/winbindd
winbind enum groups (G)
On large installations using
winbindd
(8)
it may be necessary to suppress
the enumeration of groups through the
setgrent()
getgrent()
and
endgrent()
group of system calls. If
the
winbind enum groups
parameter is
no
, calls to the
getgrent()
system
call will not return any data.
Warning
Turning off group enumeration may cause some programs to behave oddly.
Default:
winbind enum groups
no
winbind enum users (G)
On large installations using
winbindd
(8)
it may be
necessary to suppress the enumeration of users through the
setpwent()
getpwent()
and
endpwent()
group of system calls. If
the
winbind enum users
parameter is
no
, calls to the
getpwent
system call
will not return any data.
Warning
Turning off user
enumeration may cause some programs to behave oddly. For
example, the finger program relies on having access to the
full user list when searching for matching
usernames.
Default:
winbind enum users
no
winbind expand groups (G)
This option controls the maximum depth that winbindd
will traverse when flattening nested group memberships
of Windows domain groups. This is different from the
winbind nested groups
option
which implements the Windows NT4 model of local group
nesting. The "winbind expand groups"
parameter specifically applies to the membership of
domain groups.
This option also affects the return of non nested
group memberships of Windows domain users. With the
new default "winbind expand groups = 0" winbind does
not query group memberships at all.
Be aware that a high value for this parameter can
result in system slowdown as the main parent winbindd daemon
must perform the group unrolling and will be unable to answer
incoming NSS or authentication requests during this time.
The default value was changed from 1 to 0 with Samba 4.2.
Some broken applications (including some implementations of
newgrp and sg) calculate the group memberships of
users by traversing groups, such applications will require
"winbind expand groups = 1". But the new default makes winbindd
more reliable as it doesn't require SAMR access to domain
controllers of trusted domains.
Default:
winbind expand groups
winbind:ignore domains (G)
Allows one to enter a list of trusted domains winbind should
ignore (untrust). This can avoid the overhead of resources from
attempting to login to DCs that should not be communicated with.
Default:
winbind:ignore domains
Example:
winbind:ignore domains
DOMAIN1, DOMAIN2
winbind max clients (G)
This parameter specifies the maximum number of clients
the
winbindd
(8)
daemon can connect with.
The parameter is not a hard limit.
The
winbindd
(8)
daemon configures
itself to be able to accept at least that many connections,
and if the limit is reached, an attempt is made to disconnect
idle clients.
Default:
winbind max clients
200
winbind max domain connections (G)
This parameter specifies the maximum number of simultaneous
connections that the
winbindd
(8)
daemon should open to the
domain controller of one domain.
Setting this parameter to a value greater than 1 can improve
scalability with many simultaneous winbind requests,
some of which might be slow.
Changing this value requires a restart of winbindd.
Note that if
winbind offline logon
is set to
Yes
, then only one
DC connection is allowed per domain, regardless of this setting.
Default:
winbind max domain connections
Example:
winbind max domain connections
10
winbind nested groups (G)
If set to yes, this parameter activates the support for nested
groups. Nested groups are also called local groups or
aliases. They work like their counterparts in Windows: Nested
groups are defined locally on any machine (they are shared
between DC's through their SAM) and can contain users and
global groups from any trusted SAM. To be able to use nested
groups, you need to run nss_winbind.
Default:
winbind nested groups
yes
winbind normalize names (G)
This parameter controls whether winbindd will replace
whitespace in user and group names with an underscore (_) character.
For example, whether the name "Space Kadet" should be
replaced with the string "space_kadet".
Frequently Unix shell scripts will have difficulty with usernames
contains whitespace due to the default field separator in the shell.
If your domain possesses names containing the underscore character,
this option may cause problems unless the name aliasing feature
is supported by your nss_info plugin.
This feature also enables the name aliasing API which can
be used to make domain user and group names to a non-qualified
version. Please refer to the manpage for the configured
idmap and nss_info plugin for the specifics on how to configure
name aliasing for a specific configuration. Name aliasing takes
precedence (and is mutually exclusive) over the whitespace
replacement mechanism discussed previously.
Default:
winbind normalize names
no
Example:
winbind normalize names
yes
winbind nss info (G)
This parameter is designed to control how Winbind retrieves Name
Service Information to construct a user's home directory and login shell.
Currently the following settings are available:
template
- The default, using the parameters of
template
shell
and
template homedir

- When Samba is running in security = ads and your Active Directory
Domain Controller does support the Microsoft "Services for Unix" (SFU)
LDAP schema, winbind can retrieve the login shell and the home
directory attributes directly from your Directory Server. For SFU 3.0 or 3.5 simply choose
"sfu", if you use SFU 2.0 please choose "sfu20".
Note that for the idmap backend
idmap_ad
you need to configure those settings in the idmap configuration section.
Make sure to consult the documentation of the idmap backend that you are using.
Default:
winbind nss info
template
Example:
winbind nss info
sfu
winbind offline logon (G)
This parameter is designed to control whether Winbind should
allow one to login with the
pam_winbind
module using Cached Credentials. If enabled, winbindd will store user credentials
from successful logins encrypted in a local cache.
Default:
winbind offline logon
no
Example:
winbind offline logon
yes
winbind reconnect delay (G)
This parameter specifies the number of
seconds the
winbindd
(8)
daemon will wait between
attempts to contact a Domain controller for a domain that is
determined to be down or not contactable.
Default:
winbind reconnect delay
30
winbind refresh tickets (G)
This parameter is designed to control whether Winbind should refresh Kerberos Tickets
retrieved using the
pam_winbind
module.
Default:
winbind refresh tickets
no
Example:
winbind refresh tickets
yes
winbind request timeout (G)
This parameter specifies the number of
seconds the
winbindd
(8)
daemon will wait before
disconnecting either a client connection with no outstanding
requests (idle) or a client connection with a request that has
remained outstanding (hung) for longer than this number of seconds.
Default:
winbind request timeout
60
winbind rpc only (G)
Setting this parameter to
yes
forces
winbindd to use RPC instead of LDAP to retrieve information from Domain
Controllers.
Default:
winbind rpc only
no
winbind scan trusted domains (G)
This option only takes effect when the
security
option is set to
domain
or
ads
If it is set to yes, winbindd periodically tries to scan for new
trusted domains and adds them to a global list inside of winbindd.
The list can be extracted with
wbinfo --trusted-domains --verbose
Setting it to yes matches the behaviour of Samba 4.7 and older.
The construction of that global list is not reliable and often
incomplete in complex trust setups. In most situations the list is
not needed any more for winbindd to operate correctly.
E.g. for plain file serving via SMB using a simple idmap setup
with
autorid
tdb
or
ad
However some more complex setups require the list, e.g.
if you specify idmap backends for specific domains.
Some pam_winbind setups may also require the global list.
If you have a setup that doesn't require the global list, you should set
winbind scan trusted domains = no
Default:
winbind scan trusted domains
no
winbind sealed pipes (G)
This option controls whether any requests from winbindd to domain controllers
pipe will be sealed. Disabling sealing can be useful for debugging
purposes.
The behavior can be controlled per netbios domain
by using 'winbind sealed pipes:NETBIOSDOMAIN = no' as option.
Default:
winbind sealed pipes
yes
winbind separator (G)
This parameter allows an admin to define the character
used when listing a username of the form of
DOMAIN
user
. This parameter
is only applicable when using the
pam_winbind.so
and
nss_winbind.so
modules for UNIX services.
Please note that setting this parameter to + causes problems
with group membership at least on glibc systems, as the character +
is used as a special character for NIS in /etc/group.
Default:
winbind separator
Example:
winbind separator
winbind use default domain (G)
This parameter specifies whether the
winbindd
(8)
daemon should operate on users
without domain component in their username. Users without a domain
component are treated as is part of the winbindd server's own
domain. While this does not benefit Windows users, it makes SSH, FTP and
e-mail function in a way much closer to the way they
would in a native unix system.
This option should be avoided if possible. It can cause confusion
about responsibilities for a user or group. In many situations it is
not clear whether winbind or /etc/passwd should be seen as authoritative
for a user, likewise for groups.
Default:
winbind use default domain
no
Example:
winbind use default domain
yes
winbind use krb5 enterprise principals (G)
winbindd is able to get kerberos tickets for
pam_winbind with krb5_auth or wbinfo -K/--krb5auth=.
winbindd (at least on a domain member) is never be able
to have a complete picture of the trust topology (which is managed by the DCs).
There might be uPNSuffixes and msDS-SPNSuffixes values,
which don't belong to any AD domain at all.
With
winbind scan trusted domains = no
winbindd doesn't even get a complete picture of the topology.
It is not really required to know about the trust topology.
We can just rely on the [K]DCs of our primary domain (e.g. PRIMARY.A.EXAMPLE.COM)
and use enterprise principals e.g. upnfromB@B.EXAMPLE.COM@PRIMARY.A.EXAMPLE.COM
and follow the WRONG_REALM referrals in order to find the correct DC.
The final principal might be userfromB@INTERNALB.EXAMPLE.PRIVATE.
With
winbind use krb5 enterprise principals = yes
winbindd enterprise principals will be used.
Default:
winbind use krb5 enterprise principals
yes
Example:
winbind use krb5 enterprise principals
no
winbind varlink service (G)
This setting controls whether
winbind
(8)
will listen for User/Group record lookup
from
nss-systemd
(8)
via Varlink, offering an alternative
to nss_winbind.
For more information about User/Group record lookup via Varlink see
nss-systemd
(8)
manpage.
Warning
Systemd
(1)
versions prior 253 consider the default
winbind separator
'\' an unsafe character in the
GetMemberhips reply. To workaround the issue it is recommended to set it to '+'
for example.
Warning
This setting has no effect in platforms or distributions without
systemd
(1)
Default:
winbind varlink service
no
winsdb:local_owner (G)
This specifies the address that is stored in the winsOwner attribute, of
locally registered winsRecord-objects.
The default is to use the ip-address of the first network interface.
No default
winsdb:dbnosync (G)
This parameter disables fsync() after changes of the WINS database.
Default:
winsdb:dbnosync
no
wins hook (G)
When Samba is running as a WINS server this
allows you to call an external program for all changes to the
WINS database. The primary use for this option is to allow the
dynamic update of external name resolution databases such as
dynamic DNS.
The wins hook parameter specifies the name of a script
or executable that will be called as follows:
wins_hook operation name nametype ttl IP_list
The first argument is the operation and is
one of "add", "delete", or
"refresh". In most cases the operation
can be ignored as the rest of the parameters
provide sufficient information. Note that
"refresh" may sometimes be called when
the name has not previously been added, in that
case it should be treated as an add.
The second argument is the NetBIOS name. If the
name is not a legal name then the wins hook is not called.
Legal names contain only letters, digits, hyphens, underscores
and periods.
The third argument is the NetBIOS name
type as a 2 digit hexadecimal number.
The fourth argument is the TTL (time to live)
for the name in seconds.
The fifth and subsequent arguments are the IP
addresses currently registered for that name. If this list is
empty then the name should be deleted.
An example script that calls the BIND dynamic DNS update
program
nsupdate
is provided in the examples
directory of the Samba source code.
No default
wins proxy (G)
This is a boolean that controls if
nmbd
(8)
will respond to broadcast name
queries on behalf of other hosts. You may need to set this
to
yes
for some older clients.
Default:
wins proxy
no
wins server (G)
This specifies the IP address (or DNS name: IP
address for preference) of the WINS server that
nmbd
(8)
should register with. If you have a WINS server on
your network then you should set this to the WINS server's IP.
You should point this at your WINS server if you have a
multi-subnetted network.
If you want to work in multiple namespaces, you can
give every wins server a 'tag'. For each tag, only one
(working) server will be queried for a name. The tag should be
separated from the ip address by a colon.
Note
You need to set up Samba to point
to a WINS server if you have multiple subnets and wish cross-subnet
browsing to work correctly.
See the chapter in the Samba3-HOWTO on Network Browsing.
Default:
wins server
Example:
wins server
mary:192.9.200.1 fred:192.168.3.199 mary:192.168.2.61

# For this example when querying a certain name, 192.19.200.1 will
be asked first and if that doesn't respond 192.168.2.61. If either
of those doesn't know the name 192.168.3.199 will be queried.
Example:
wins server
192.9.200.1 192.168.2.61
wins support (G)
This boolean controls if the
nmbd
(8)
process in Samba will act as a WINS server. You should
not set this to
yes
unless you have a multi-subnetted network and
you wish a particular
nmbd
to be your WINS server.
Note that you should
NEVER
set this to
yes
on more than one machine in your network.
Default:
wins support
no
workgroup (G)
This controls what workgroup your server will
appear to be in when queried by clients. Note that this parameter
also controls the Domain name used with
the
security = domain
setting.
Default:
workgroup
WORKGROUP
Example:
workgroup
MYGROUP
wreplsrv:periodic_interval (G)
This maximum interval in seconds between 2 periodically scheduled runs
where we check for wins.ldb changes and do push notifications to our
push partners. Also wins_config.ldb changes are checked in that
interval and partner configuration reloads are done.
Default:
wreplsrv:periodic_interval
15
wreplsrv:propagate name releases (G)
If this parameter is enabled, then
explicit (from the client) and implicit (via the scavenging) name releases
are propagated to the other servers directly, even if there are still other
addresses active, this applies to SPECIAL GROUP (2) and MULTIHOMED (3) entries.
Also the replication conflict merge algorithm for SPECIAL GROUP (2) entries
discards replica addresses where the address owner is the local server,
if the address was not stored locally before. The merge result is
propagated directly in case an address was discarded.
A Windows servers doesn't propagate name releases of SPECIAL GROUP (2)
and MULTIHOMED (3) entries directly, which means that Windows servers may
return different results to name queries for SPECIAL GROUP (2) and MULTIHOMED (3)
names. The option doesn't have much negative impact if Windows servers are
around, but be aware that they might return unexpected results.
Default:
wreplsrv:propagate name releases
no
wreplsrv:scavenging_interval (G)
This is the interval in s between 2 scavenging runs which
clean up the WINS database and changes the states of expired name records.
Defaults to half of the value of wreplsrv:renew_interval.
No default
wreplsrv:tombstone_extra_timeout (G)
This is the time in s the server needs to be up till we'll remove
tombstone records from our database. Defaults to 3 days.
Default:
wreplsrv:tombstone_extra_timeout
259200
wreplsrv:tombstone_interval (G)
This is the interval in s till released records of the WINS
server become tombstone. Defaults to 6 days.
Default:
wreplsrv:tombstone_interval
518400
wreplsrv:tombstone_timeout (G)
This is the interval in s till tombstone records are deleted from
the WINS database. Defaults to 1 day.
Default:
wreplsrv:tombstone_timeout
86400
wreplsrv:verify_interval (G)
This is the interval in s till we verify active replica records
with the owning WINS server. Unfortunately not implemented yet.
Defaults to 24 days.
Default:
wreplsrv:verify_interval
2073600
writable
This parameter is a synonym for
writeable
write ok
This parameter is a synonym for
writeable
writeable (S)
Inverted synonym for
read only
Default:
writeable
no
write list (S)
This is a list of users that are given read-write access to a service. If the
connecting user is in this list then they will be given write access, no matter
what the
read only
option is set to. The list can
include group names using the @group syntax.
Note that if a user is in both the read list and the write list then they will be
given write access.
Default:
write list
Example:
write list
admin, root, @staff
write raw (G)
This is ignored if
async smb echo handler
is set,
because this feature is incompatible with raw write SMB requests
If enabled, raw writes allow writes of 65535 bytes in
one packet. This typically provides a major performance benefit for some very, very old clients.
However, some clients either negotiate the allowable
block size incorrectly or are incapable of supporting larger block
sizes, and for these clients you may need to disable raw writes.
In general this parameter should be viewed as a system tuning
tool and left severely alone.
Default:
write raw
yes
wsp property file (G)
wsp property file
parameter.
This parameter specifies the file where additional WSP Windows Search Protocol properties
are stored. The format of the file is a csv consisting of 10 comma separated columns. The
first 3 columns are required, the other columns are desirable but not necessary.
Property Name
A property name e.g. System.ItemUrl.
GUID
A guid that identifies the propertyset the property belongs to.
prop ID
A number that together with the GUID uniquely identifies the property.
inInverted Index
Set to TRUE is the property is indexed.
isColumn
Set to TRUE if the property is one that can be returned in rows returned from WSP query.
type
One of
Boolean
Buffer
Byte
DateTime
Double
Int32
String
UInt16
UInt32
UInt64
MaxSize
maximum size when stored.
Vector Property
TRUE if this is a multivalue property.
Description
Description of what the property is used for.
Default:
wsp property file
wtmp directory (G)
This parameter is only available if Samba has been configured and compiled with the option
--with-utmp
. It specifies a directory pathname that is used to store the wtmp or wtmpx files (depending on
the UNIX system) that record user connections to a Samba server. The difference with the utmp directory is the fact
that user info is kept after a user has logged out.
By default this is not set, meaning the system will use whatever utmp file the native system is set to use (usually
/var/run/wtmp
on Linux).
Default:
wtmp directory
Example:
wtmp directory
/var/log/wtmp
WARNINGS
Although the configuration file permits service names to contain spaces, your client software may not.
Spaces will be ignored in comparisons anyway, so it shouldn't be a problem - but be aware of the possibility.
On a similar note, many clients - especially DOS clients - limit service names to eight characters.
smbd
(8)
has no such
limitation, but attempts to connect from such clients will fail if they truncate the service names. For this
reason you should probably keep your service names down to eight characters in length.
Use of the
[homes]
and
[printers]
special sections make life
for an administrator easy, but the various combinations of default attributes can be tricky. Take extreme
care when designing these sections. In particular, ensure that the permissions on spool directories are
correct.
VERSION
This man page is part of version 4.23.0 of the Samba suite.
SEE ALSO
samba
(7)
smbpasswd
(8)
smbd
(8)
nmbd
(8)
winbindd
(8)
samba
(8)
samba-tool
(8)
smbclient
(1)
nmblookup
(1)
testparm
(1)
AUTHOR
The original Samba software and related utilities were created by Andrew Tridgell. Samba is now developed
by the Samba Team as an Open Source project similar to the way the Linux kernel is developed.