name = value 

[foo]
path = /home/bar
read only = no

[aprinter]
path = /var/tmp
read only = yes
printable = yes
guest ok = yes

mkdir /usr/local/samba/lib/usershares
chgrp foo /usr/local/samba/lib/usershares
chmod 1770 /usr/local/samba/lib/usershares

usershare path = /usr/local/samba/lib/usershares
usershare max shares = 10 # (or the desired number of shares)

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 smb ports = 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.

Before 4.0.0 it could contain IPv4 mapped IPv6 addresses, now it only contains IPv4 or IPv6 addresses.

Before 4.0.0 it could contain IPv4 mapped IPv6 addresses, now it only contains IPv4 or IPv6 addresses.

[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

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

Default: access based share enum = no

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

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

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 :

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

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

Default: acl map full control = yes

Possible values are :

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.

Example: ad dc functional level = 2016

Default: add group script =

Example: add group script = /usr/sbin/groupadd %g

Default: additional dns hostnames = # empty string (no additional dns names)

Example: additional dns hostnames = host2.example.com host3.other.com

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

Default: addport command =

Example: addport command = /etc/samba/scripts/addport.sh

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):

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

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.

Default: add share command =

Example: add share command = /usr/local/bin/addshare

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

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

See the section below on security for more information about this option.

Default: administrative share = no

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

Default: afs share = no

Set this parameter to 0 to get NEVERDATE.

Default: afs token lifetime = 604800

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

Related command: aio read size

Related command: aio write size

Default: aio max threads = 100

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 = 1

Example: aio read size = 0 # Always do reads synchronously

The syntax is identical to the veto files parameter.

Default: aio write behind =

Example: aio write behind = /*.tmp/

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 = 1

Example: aio write size = 0 # Always do writes synchronously

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

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 = 0

Example: allocation roundup size = 1048576 # (to set it to the former default of 1 MiB)

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

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

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

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 https://bugzilla.samba.org/show_bug.cgi?id=15240

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' and/or 'reject md5 clients' options.

Default: allow nt4 crypto = no

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, https://bugzilla.samba.org/show_bug.cgi?id=15240.

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' and/or 'reject md5 clients' options.

Which means 'allow nt4 crypto:COMPUTERACCOUNT = yes' is only useful in combination with 'server reject md5 schannel:COMPUTERACCOUNT = no'

	allow nt4 crypto:LEGACYCOMPUTER1$ = yes
	server reject md5 schannel:LEGACYCOMPUTER1$ = no
	allow nt4 crypto:NASBOX$ = yes
	server reject md5 schannel:NASBOX$ = no
	allow nt4 crypto:LEGACYCOMPUTER2$ = yes
	server reject md5 schannel:LEGACYCOMPUTER2$ = no

No default

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

Default: allow unsafe cluster upgrade = no

Default: apply group policies = no

Example: apply group policies = yes

The minimum value of this parameter is clamped at 1 second.

Default: async dns timeout = 10

Example: async dns timeout = 20

Default: async smb echo handler = no

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

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

Default: available = yes

Default: binddns dir = /var/lib/samba/bind-dns

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

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

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

Default: browseable = yes

Default: browse list = yes

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 = /var/cache/samba

Example: cache directory = /var/run/samba/locks/cache

Default: case sensitive = auto

You should never need to change this parameter

Default: change notify = yes

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.

Default: change share command =

Example: change share command = /usr/local/bin/changeshare

Default: check parent directory delete on close = no

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:

Default: check password script = # Disabled

Example: check password script = /usr/local/sbin/crackcheck

Default: cldap port = 389

Example: cldap port = 3389

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

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

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

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

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

Possible values are :

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

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

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

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

Possible client settings are:

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

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

Effects for SMB1

Effects for SMB3 and newer

Default: client smb encrypt = default

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

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

Possible option settings are:

Default: client use kerberos = desired

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

Default: cluster addresses =

Example: cluster addresses = 10.0.0.1 10.0.0.2 10.0.0.3

Set this parameter to yes only if you have a cluster setup with ctdb running.

Default: clustering = no

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

Note: This option can not be set inside the registry configuration itself.

Default: config backend = file

Example: config backend = registry

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

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

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

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

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

Default: ctdbd socket =

Example: ctdbd socket = /tmp/ctdb.socket

The default value of 0 disables this logging.

Default: ctdb locktime warn threshold = 0

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 = 0

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

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

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"

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

Default: dcerpc endpoint servers = epmapper, wkssvc, samr, netlogon, lsarpc, drsuapi, dssetup, unixinfo, browser, eventlog6, backupkey, dnsserver

Example: dcerpc endpoint servers = rpcecho

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

For more information about currently available debug classes, see section about log level.

Default: debug class = no

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

Note that the parameter debug timestamp or debug syslog format must be on for this to have an effect.

Default: debug hires timestamp = yes

Note that the parameter debug timestamp must be on for this to have an effect.

Default: debug pid = no

Note that this parameter overrides the debug timestamp parameter.

Default: debug prefix timestamp = no

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

Default: winbind debug traceid = yes

Note that the parameter debug timestamp must be on for this to have an effect.

Default: debug uid = no

Default: dedicated keytab file =

Example: dedicated keytab file = /usr/local/etc/krb5.keytab

Default: default case = lower

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

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

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

Default: delete group script =

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

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

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.

Default: delete share command =

Example: delete share command = /usr/local/bin/delshare

Default: delete user from group script =

Example: delete user from group script = /usr/sbin/deluser %u %g

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

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

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

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

Default: dgram port = 138

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

No default

Default: disable spoolss = no

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

This value is used either register with AD during a join or by calling

        net ads dns register

or during Kerberos authentication to create service principal names. This
is not supported in samba-tool yet.

Default: dns hostname = [netbios name].[realm]

Example: dns hostname = client-hostname.example.com

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

It makes possible to use another DNS server as a front and forward to Samba.

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

Default: dns update command = /build/samba/src/samba-4.21.1/source4/scripting/bin/samba_dnsupdate

Example: dns update command = /usr/local/sbin/dnsupdate

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

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

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

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

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

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

Default: dos filemode = no

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

Default: dos filetimes = yes

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

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

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

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

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

Default: elasticsearch:address = localhost

Example: elasticsearch:address = needle.haystack.samba.org

Default: elasticsearch:ignore unknown attribute = no

Example: elasticsearch:ignore unknown attribute = yes

Default: elasticsearch:ignore unknown type = no

Example: elasticsearch:ignore unknown type = yes

Default: elasticsearch:index = _all

Example: elasticsearch:index = spotlight

Default: elasticsearch:mappings = /usr/share/samba/elasticsearch_mappings.json

Example: elasticsearch:mappings = /usr/share/foo/mymappings.json

Default: elasticsearch:max results = 100

Example: elasticsearch:max results = 10

Default: elasticsearch:port = 9200

Example: elasticsearch:port = 9201

Default: elasticsearch:use tls = no

Example: elasticsearch:use tls = yes

Default: enable asu support = no

Default: enable core files = yes

Example: enable core files = no

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

Default: enable spoolss = yes

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

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

Default: enumports command =

Example: enumports command = /usr/bin/listports

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

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

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

This option is enabled (i.e. smbd will follow symbolic links) by default.

Default: follow symlinks = yes

This option should not be changed from the default unless you know what you're doing.

Default: smbd force process locks = no

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

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

No default

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

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

No default

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

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

Default: fss: prune stale = no

Example: fss: prune stale = yes

Default: fss: sequence timeout = 180 or 1800, depending on operation

Example: fss: sequence timeout = 0

Default: fstype = NTFS

Example: fstype = Samba

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:

The type of query can be one of:

Example: get quota command = /usr/local/sbin/query_quota

Default: getwd cache = yes

Default: gpo update command = /build/samba/src/samba-4.21.1/source4/scripting/bin/samba-gpupdate

Example: gpo update command = /usr/local/sbin/gpoupdate

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

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

See the section below on security for more information about this option.

Default: guest only = no

Default: hide dot files = yes

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

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 = 0

Default: hide special files = no

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

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

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

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

Default: hostname lookups = no

Example: hostname lookups = yes

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

Default: hosts allow = # none (i.e., all hosts permitted access)

Example: hosts allow = 150.203.5. myhost.mynet.edu.au

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

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

Default: idmap cache time = 604800

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

range = low - high

read only = yes|no

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

See the idmap config option.

Default: idmap gid =

Example: idmap gid = 10000-20000

Default: idmap negative cache time = 120

See the idmap config option.

Default: idmap uid =

Example: idmap uid = 10000-20000

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

Default: include system krb5 conf = yes

Default: inherit acls = no

Valid options are:

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

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

Default: init logon delay = 100

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

The option takes a list of interface strings. Each string can be in any of the following forms:

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"

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

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

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:

This option is mostly for testing and currently only applies if the embedded Heimdal KDC is used.

Default: kdc enable fast = yes

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

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:

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

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 https://bugzilla.samba.org/show_bug.cgi?id=15237.

Default: kerberos encryption types = all

Valid options are:

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

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 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 a 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 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

Default: kpasswd port = 464

Default: krb5 port = 88

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

Default: large readwrite = yes

The ldap admin dn requires a fully specified DN. The ldap suffix is not appended to the ldap admin dn.

No default

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 = 2

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 = 0

Example: ldap debug level = 1

Default: ldap debug threshold = 10

Example: ldap debug threshold = 5

Default: ldap delete dn = no

Default: ldap deref = auto

Example: ldap deref = searching

Default: ldap follow referral = auto

Example: ldap follow referral = off

Default: ldap group suffix =

Example: ldap group suffix = ou=Groups

Default: ldap idmap suffix =

Example: ldap idmap suffix = ou=Idmap

Default: ldap machine suffix =

Example: ldap machine suffix = ou=Computers

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

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

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

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

The ldap passwd sync can be set to one of three values:

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

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

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

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 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:

Default: ldap ssl = start tls

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

Default: ldap timeout = 15

Default: ldap user suffix =

Example: ldap user suffix = ou=people

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

Default: lm announce = auto

Example: lm announce = yes

Default: lm interval = 60

Example: lm interval = 120

Default: load printers = yes

Setting this value to no will cause nmbd never to become a local master browser.

Default: local master = yes

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 = /var/cache/samba

Example: lock directory = /var/run/samba/locks

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

Default: lock spin time = 200

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

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:

Default: logging =

Example: logging = syslog@1 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:

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:

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:

Log levels for dsdb_password_audit and dsdb_password_json_audit are:

Log levels for dsdb_transaction_audit and dsdb_transaction_json are:

Example: log level = 3 passdb:5 auth:10 winbind:2

Example: log level = 1 full_audit:1@/var/log/audit.log winbind:2

This is only useful for development purposes.

Default: log nt token command =

Note that this option is only useful if Samba is set up as a logon server.

Default: logon drive =

Example: logon drive = h:

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

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 MANdatory 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.

Disable the use of roaming profiles by setting the value of this parameter to the empty string. For example, logon path = "". 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

Default: logon path = \\%N\%U\profile

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

Default: log writeable files on exit = no

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

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

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

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

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

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

See also smbpasswd(8), and the security = domain and security = ads parameters.

Default: machine password timeout = 604800

Example: magic output = myfile.txt

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

See the section on name mangling for details on how to control the mangling process.

Possible option settings are

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 is effective only when mangling method is hash2.

Default: mangle prefix = 1

Example: mangle prefix = 4

Default: mangling char = ~

Example: mangling char = ^

Default: mangling method = hash2

Example: mangling method = hash

Default: map acl inherit = no

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

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

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 :

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

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

The four settings are :

Default: map to guest = Never

Example: map to guest = Bad User

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 = 0

Example: max connections = 10

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.

A max disk size of 0 means no limit.

Default: max disk size = 0

Example: max disk size = 1000

A size of 0 means no limit.

Default: max log size = 5000

Example: max log size = 1000

Default: max mux = 50

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

Default: max print jobs = 1000

Example: max print jobs = 5000

Default: max reported print jobs = 0

Example: max reported print jobs = 1000

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 = 0

Example: max smbd processes = 1000

Default: max stat cache size = 512

Example: max stat cache size = 100

Default: max ttl = 259200

Default: max wins ttl = 518400

Default: max xmit = 16644

Example: max xmit = 8192

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

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:

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' &

Note that this option interacts with the configured idmap ranges!

Default: min domain uid = 1000

Default: min print space = 0

Example: min print space = 2000

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 = 0

Default: min wins ttl = 21600

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 =

Example: mit kdc command = /opt/mit/sbin/krb5kdc

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

Default: msdfs root = no

Default: msdfs shuffle referrals = no

This parameter allows disabling Samba to register itself.

Default: multicast dns register = yes

Default: name cache timeout = 660

Example: name cache timeout = 0

The options are: "lmhosts", "host", "wins" and "bcast". They cause names to be resolved as follows:

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

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

Default: nbtd:wins_prepend1Bto1Cqueries = yes

Default: nbtd:wins_wins_randomize1Clist = no

Default: nbtd:wins_randomize1Clist_mask = 255.255.255.0

Default: nbt port = 137

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 = /run/samba/ncalrpc

Example: ncalrpc dir = /var/run/samba/ncalrpc

Default: netbios aliases = # empty string (no additional names)

Example: netbios aliases = TEST TEST1 TEST2

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

Default: netbios scope =

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

Default: nmbd bind explicit broadcast = yes

Default: nsupdate command = /usr/bin/nsupdate -g

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:

Default: nt acl support = yes

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:

Default: ntlm auth = ntlmv2-only

Default: nt pipe support = yes

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 = /var/lib/samba/ntp_signd

You should not need to ever disable this parameter.

Default: nt status support = yes

Default: ntvfs handler = unixuid, default

See also smbpasswd(5).

Default: null passwords = no

Default: obey pam restrictions = no

This parameter only applies when server role is set to Active Directory Domain Controller.

Default: old password allowed period = 60

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

<nt driver name> = <os2 driver name>.<device name>

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 =

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

Default: pam password change = no

Default: panic action =

Example: panic action = /bin/sleep 90000

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:

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

Default: passdb expand explicit = no

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*"

Default: passwd chat debug = no

Default: passwd chat timeout = 2

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

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

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:

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

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 *

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

No default

Default: pid directory = /run

Example: pid directory = /var/run/

Default: posix locking = yes

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

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

Default: preexec close = no

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

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

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 = 4

Default: prefork maximum backoff = 120

Default: preload modules =

Example: preload modules = /usr/lib/samba/passdb/mysql.so

See the section on NAME MANGLING for a fuller discussion.

Default: preserve case = yes

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

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

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.

Example: printcap name = /etc/myprintcap

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

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

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

Default: printjob username = %U

Example: printjob username = %D\%U

Default: print notify backchannel = no

Default: private dir = /var/lib/samba/private

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

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

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

Default: read list =

Example: read list = mary, @students

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

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

Default: realm =

Example: realm = mysambabox.mycompany.com

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

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 https://www.samba.org/samba/security/CVE-2022-38023.html for more details.

The default changed from 'no' to 'yes', with the patches for CVE-2022-38023 see https://bugzilla.samba.org/show_bug.cgi?id=15240.

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 https://bugzilla.samba.org/show_bug.cgi?id=15240.

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'.

Default: reject md5 clients = yes

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, https://bugzilla.samba.org/show_bug.cgi?id=15240.

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'.

	server reject md5 schannel:LEGACYCOMPUTER1$ = no
	server reject md5 schannel:NASBOX$ = no
	server reject md5 schannel:LEGACYCOMPUTER2$ = no

No default

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 overrides the require strong key option.

Default: reject md5 servers = yes

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 =

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 =

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.

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

Default: reset on zero vc = no

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 = 0

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

Default: root postexec =

Default: root preexec =

Default: root preexec close = no

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

This applies to RPC servers in all server roles.

Default: rpc server dynamic port range = 49152-65535

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 = 0

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

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 = /build/samba/src/samba-4.21.1/source4/scripting/bin/samba_kcc

Example: samba kcc command = /usr/local/bin/kcc

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

No default

An empty list means to offer a share on all interfaces.

Default: server addresses =

Possible values are :

Default: server max protocol = SMB3

Example: server max protocol = LANMAN1

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

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

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 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

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), https://bugzilla.samba.org/show_bug.cgi?id=14497.

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

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), https://bugzilla.samba.org/show_bug.cgi?id=14497.

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

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 https://bugzilla.samba.org/show_bug.cgi?id=15240.

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

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, https://bugzilla.samba.org/show_bug.cgi?id=15240.

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

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, winbindd, ntp_signd, kcc, dnsupdate, dns

Example: server services = -s3fs, +smb

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

Effects for SMB1

Effects for SMB2 and newer

Default: server smb encrypt = default

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

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

It also sets what will appear in browse lists next to the machine name.

A %v will be replaced with the Samba version number.

A %h will be replaced with the hostname.

Default: server string = Samba %v

Example: server string = University of GNUs Samba Server

Default: set primary group script =

Example: set primary group script = /usr/sbin/usermod -g '%g' '%u'

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:

Default: set quota command =

Example: set quota command = /usr/local/sbin/set_quota

Default: share:fake_fscaps = 0

See the section on NAME MANGLING.

Default: short preserve case = yes

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.

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:

#!/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

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

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

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

This is only available with oplocks = yes and kernel oplocks = no.

Default: smb2 leases = yes

The default is 8192 credits, which is the same as a Windows 2008R2 SMB2 server.

Default: smb2 max credits = 8192

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

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

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

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

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

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

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

Default: smb3 unix extensions = no

Default: smbd async dosmode = no

Default: smbd getinfo ask sharemode = yes

Default: smbd max async dosmode = aio max threads * 2

Default: smbd max xattr size = 65536

Possible values are off, count and on.

Default: smbd profiling level = off

Example: smbd profiling level = on

Default: smbd search ask sharemode = yes

Default: smb encrypt = default

An example of use is:

smb passwd file = /etc/samba/smbpasswd

Default: smb passwd file = /var/lib/samba/private/smbpasswd

Default: smb ports = 445 139

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:

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

Default: spn update command = /build/samba/src/samba-4.21.1/source4/scripting/bin/samba_spnupdate

Example: spn update command = /usr/local/sbin/spnupdate

Default: spoolss: architecture = Windows x64

Example: spoolss: architecture = Windows NT x86

Default: spoolss: os_major = 5

Example: spoolss: os_major = 6

Default: spoolss: os_minor = 0

Example: spoolss: os_minor = 1

Default: spoolss: os_build = 2195

Example: spoolss: os_build = 7601

Default: spoolss_client: os_major = 6

Default: spoolss_client: os_minor = 1

Default: spoolss_client: os_build = 7007

Spotlight has several prerequisites:

Default: spotlight = no

Default: spotlight backend = noindex

Default: stat cache = yes

This option specifies the directory where TDB files containing important persistent data will be stored.

Default: state directory = /var/lib/samba

Example: state directory = /var/run/samba/locks/state

Default: store dos attributes = yes

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

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

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.

Default: strict rename = no

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

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

Default: sync always = no

If keytabs should be generated in clustered environments it is recommended to update them on all nodes. You can set the config option to /usr/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 = /usr/share/ctdb/scripts/winbind_ctdb_updatekeytab.sh

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[:sync_etypes][:sync_kvno][:netbios_aliases][:additional_dns_hostnames][:machine_password]

where spn_spec can have exactly one of these four forms:

account_name
sync_spns
spn_prefixes=value1[,value2[...]]
spns=value1[,value2[...]]

No other combinations are allowed.

Specifiers:

account_name - creates entry using principal 'computer$@REALM'.
sync_spns    - uses principals received from AD DC.
spn_prefixes - creates principals from the prefixes and adds netbios_aliases or additional_dns_hostnames if specified.
spns         - creates only the principals defined in the list.

Options:

sync_etypes              - parameter "msDS-SupportedEncryptionTypes" is read from DC and is used to find the highest common enc type for AD and KRB5 lib.
sync_kvno                - the key version number ("msDS-KeyVersionNumber") is synchronized from DC, otherwise is set to -1.
netbios_aliases          - evaluated only for SPN_SPEC_PREFIX. If present, PREFIX/netbiosname@REALM and PREFIX/netbiosname.domainname@REALM are added for each alias. See netbios aliases
additional_dns_hostnames - evaluated only for SPN_SPEC_PREFIX. If present, PREFIX/dnshostname@REALM is  added for each dns name. See additional dns hostnames
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"

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:

/path/to/keytab:sync_spns:sync_kvno:machine_password

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

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 = 1

The logging parameter should be used instead. When logging is set, it overrides the syslog only parameter.

Default: syslog only = no

Default: template homedir = /home/%D/%U

Default: template shell = /bin/false

Default: time server = no

Default: timestamp logs = yes

No default

This path is relative to private dir if the path does not start with a /.

Default: tls cafile = tls/ca.pem

This path is relative to private dir if the path does not start with a /.

Default: tls certfile = tls/cert.pem

This path is relative to private dir if the path does not start with a /.

Default: tls crlfile =

This path is relative to private dir if the path does not start with a /.

Default: tls dh params file =

Default: tls enabled = yes

This path is relative to private dir if the path does not start with a /.

Default: tls keyfile = tls/key.pem

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

Please use this with care, as it really means trusting all CAs installed on the system!

Default: tls trust system cas = no

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

If this option is set to false, the use of ASCII will be forced.

Default: unicode = yes

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

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

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