smb.conf — The configuration file for the Samba suite
The smb.conf file is a configuration file for the Samba suite. smb.conf contains runtime configuration information for the Samba programs. The
smb.conf file is designed to be configured and administered by the
swat(8) program. The
complete description of the file format and possible parameters held within are here for reference purposes.
The file consists of sections and parameters. A section begins with the name of the section in square brackets and continues until the next section begins. Sections contain parameters of the form:
name=value
The file is line-based - that is, each newline-terminated line represents either a comment, a section name or a parameter.
Section and parameter names are not case sensitive.
Only the first equals sign in a parameter is significant. Whitespace before or after the first equals sign is discarded. Leading, trailing and internal whitespace in section and parameter names is irrelevant. Leading and trailing whitespace in a parameter value is discarded. Internal whitespace within a parameter value is retained verbatim.
Any line beginning with a semicolon (“;”) or a hash (“#”) character is ignored, as are lines containing only whitespace.
Any line ending in a “\” is continued on the next line in the customary UNIX fashion.
The values following the equals sign in parameters are all either a string (no quotes needed) or a boolean, which may be given as yes/no, 0/1 or true/false. Case is not significant in boolean values, but is preserved in string values. Some items such as create masks are numeric.
Each section in the configuration file (except for the [global] section) describes a shared resource (known as a “share”). The section name is the name of the shared resource and the parameters within the section define the shares attributes.
There are three special sections, [global], [homes] and [printers], which are described under special sections. The following notes apply to ordinary section descriptions.
A share consists of a directory to which access is being given plus a description of the access rights which are granted to the user of the service. Some housekeeping options are also specifiable.
Sections are either file share services (used by the client as an extension of their native file systems) or printable services (used by the client to access print services on the host running the server).
Sections may be designated guest services, in which case no password is required to access them. A specified UNIX guest account is used to define access privileges in this case.
Sections other than guest services will require a password to access them. The client provides the
username. As older clients only provide passwords and not usernames, you may specify a list of usernames to
check against the password using the user = option in the share definition. For modern clients
such as Windows 95/98/ME/NT/2000, this should not be necessary.
The access rights granted by the server are masked by the access rights granted to the specified or guest UNIX user by the host system. The server does not grant more access than the host system grants.
The following sample section defines a file space share. The user has write access to the path /home/bar. The share is accessed via the share name foo:
[foo]
path = /home/bar
read only = no
The following sample section defines a printable share. The share is read-only, but printable. That is, the only write access permitted is via calls to open, write to and close a spool file. The guest ok parameter means access will be permitted as the default guest user (specified elsewhere):
[aprinter]
path = /usr/spool/public
read only = yes
printable = yes
guest ok = yes
Parameters in this section apply to the server as a whole, or are defaults for sections that do not specifically define certain items. See the notes under PARAMETERS for more information.
If a section called [homes] is included in the configuration file, services connecting clients to their home directories can be created on the fly by the server.
When the connection request is made, the existing sections are scanned. If a match is found, it is used. If no match is found, the requested section name is treated as a username and looked up in the local password file. If the name exists and the correct password has been given, a share is created by cloning the [homes] section.
Some modifications are then made to the newly created share:
The share name is changed from homes to the located username.
If no path was given, the path is set to the user's home directory.
If you decide to use a path = line in your [homes] section, it may be useful to use the %S macro. For example:
path = /data/pchome/%S
is useful if you have different home directories for your PCs than for UNIX access.
This is a fast and simple way to give a large number of clients access to their home directories with a minimum of fuss.
A similar process occurs if the requested section name is “homes”, except that the share name is not changed to that of the requesting user. This method of using the [homes] section works well if different users share a client PC.
The [homes] section can specify all the parameters a normal service section can specify, though some make more sense than others. The following is a typical and suitable [homes] section:
[homes]
read only = no
An important point is that if guest access is specified in the [homes] section, all home directories will be visible to all clients without a password. In the very unlikely event that this is actually desirable, it is wise to also specify read only access.
The browseable flag for auto home directories will be inherited from the global browseable flag, not the [homes] browseable flag. This is useful as it means setting browseable = no in the [homes] section will hide the [homes] share but make any auto home directories visible.
This section works like [homes], but for printers.
If a [printers] section occurs in the configuration file, users are able to connect to any printer specified in the local host's printcap file.
When a connection request is made, the existing sections are scanned. If a match is found, it is used. If no match is found, but a [homes] section exists, it is used as described above. Otherwise, the requested section name is treated as a printer name and the appropriate printcap file is scanned to see if the requested section name is a valid printer share name. If a match is found, a new printer share is created by cloning the [printers] section.
A few modifications are then made to the newly created share:
The share name is set to the located printer name
If no printer name was given, the printer name is set to the located printer name
If the share does not permit guest access and no username was given, the username is set to the located printer name.
The [printers] service MUST be printable - if you specify otherwise, the server will refuse to load the configuration file.
Typically the path specified is that of a world-writeable spool directory with the sticky bit set on it. A typical [printers] entry looks like this:
[printers]
path = /usr/spool/public
guest ok = yes
printable = yes
All aliases given for a printer in the printcap file are legitimate printer names as far as the server is concerned. If your printing subsystem doesn't work like that, you will have to set up a pseudo-printcap. This is a file consisting of one or more lines like this:
alias|alias|alias|alias...
Each alias should be an acceptable printer name for your printing subsystem. In the [global] section, specify the new file as your printcap. The server will only recognize names found in your pseudo-printcap, which of course can contain whatever aliases you like. The same technique could be used simply to limit access to a subset of your local printers.
An alias, by the way, is defined as any component of the first entry of a printcap record. Records are separated by newlines,
components (if there are more than one) are separated by vertical bar symbols (|).
On SYSV systems which use lpstat to determine what printers are defined on the system you may be able to use
printcap name = lpstat to automatically obtain a list of printers. See the
printcap name option for more details.
Starting with Samba version 3.0.23 the capability for non-root users to add, modify, and delete their own share definitions has been added. This capability is called usershares and is controlled by a set of parameters in the [global] section of the smb.conf. The relevant parameters are :
Controls if usershares can permit guest access.
Maximum number of user defined shares allowed.
If set only directories owned by the sharing user can be shared.
Points to the directory containing the user defined share definitions. The filesystem permissions on this directory control who can create user defined shares.
Comma-separated list of absolute pathnames restricting what directories can be shared. Only directories below the pathnames in this list are permitted.
Comma-separated list of absolute pathnames restricting what directories can be shared. Directories below the pathnames in this list are prohibited.
Names a pre-existing share used as a template for creating new usershares. All other share parameters not specified in the user defined share definition are copied from this named share.
To allow members of the UNIX group foo to create user defined
shares, create the directory to contain the share definitions as follows:
Become root:
mkdir /usr/local/samba/lib/usershares chgrp foo /usr/local/samba/lib/usershares chmod 1770 /usr/local/samba/lib/usershares
Then add the parameters
usershare path = /usr/local/samba/lib/usershares usershare max shares = 10 # (or the desired number of shares)
to the global
section of your smb.conf. Members of the group foo may then manipulate the user defined shares
using the following commands.
To create or modify (overwrite) a user defined share.
To delete a user defined share.
To list user defined shares.
To print information about user defined shares.
Parameters define the specific attributes of sections.
Some parameters are specific to the [global] section (e.g., security). Some parameters are usable in all sections (e.g., create mask). All others are permissible only in normal sections. For the purposes of the following descriptions the [homes] and [printers] sections will be considered normal. The letter G in parentheses indicates that a parameter is specific to the [global] section. The letter S indicates that a parameter can be specified in a service specific section. All S parameters can also be specified in the [global] section - in which case they will define the default behavior for all services.
Parameters are arranged here in alphabetical order - this may not create best bedfellows, but at least you can find them! Where there are synonyms, the preferred synonym is described, others refer to the preferred synonym.
Many of the strings that are settable in the config file can take substitutions. For example the option “path = /tmp/%u” is interpreted as “path = /tmp/john” if the user connected with the username john.
These substitutions are mostly noted in the descriptions below, but there are some general substitutions which apply whenever they might be relevant. These are:
session username (the username that the client wanted, not necessarily the same as the one they got).
primary group name of %U.
the Internet hostname that Samba is running on.
the NetBIOS name of the client machine (very useful).
This parameter is not available when Samba listens on port 445, as clients no longer
send this information. If you use this macro in an include statement on a domain that has
a Samba domain controller be sure to set in the [global] section 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.
the NetBIOS name of the server. This allows you to change your config based on what the client calls you. Your server can have a “dual personality”.
the Internet name of the client machine.
the selected protocol level after protocol negotiation. It can be one of CORE, COREPLUS, LANMAN1, LANMAN2 or NT1.
the process id of the current server process.
The architecture of the remote
machine. It currently recognizes Samba (Samba),
the Linux CIFS file system (CIFSFS), OS/2, (OS2),
Windows for Workgroups (WfWg), Windows 9x/ME
(Win95), Windows NT (WinNT),
Windows 2000 (Win2K),
Windows XP (WinXP),
Windows XP 64-bit(WinXP64),
Windows 2003 including
2003R2 (Win2K3), and Windows
Vista (Vista). Anything else will be known as
UNKNOWN.
the IP address of the client machine.
the local IP address to which a client connected.
the current date and time.
name of the domain or workgroup of the current user.
the winbind separator.
envvar)the value of the environment variable
envar.
The following substitutes apply only to some configuration options (only those that are used when a connection has been established):
the name of the current service, if any.
the root directory of the current service, if any.
username of the current service, if any.
primary group name of %u.
the home directory of the user given by %u.
the name of your NIS home directory server. This is obtained from your NIS auto.map entry. If you have not compiled Samba with the --with-automount option, this value will be the same as %L.
the path of the service's home directory, obtained from your NIS auto.map entry. The NIS
auto.map entry is split up as %N:%p.
There are some quite creative things that can be done with these substitutions and other
smb.conf options.
Samba supports name mangling so that DOS and Windows clients can use files that don't
conform to the 8.3 format. It can also be set to adjust the case of 8.3 format filenames.
There are several options that control the way mangling is performed, and they are grouped here rather than listed separately. For the defaults look at the output of the testparm program.
These options can be set separately for each service.
The options are:
controls whether filenames are case sensitive. If they aren't, Samba must do a filename search and match on passed names. The default setting of auto allows clients that support case sensitive filenames (Linux CIFSVFS and smbclient 3.0.5 and above currently) to tell the Samba server on a per-packet basis that they wish to access the file system in a case-sensitive manner (to support UNIX case sensitive semantics). No Windows or DOS system supports case-sensitive filename so setting this option to auto is that same as setting it to no for them. Default auto.
controls what the default case is for new filenames (ie. files that don't currently exist in the filesystem). Default lower. IMPORTANT NOTE: This option will be used to modify the case of all incoming client filenames, not just new filenames if the options case sensitive = yes, preserve case = No, short preserve case = No are set. This change is needed as part of the optimisations for directories containing large numbers of files.
controls whether new files (ie. files that don't currently exist in the filesystem) are created with the case
that the client passes, or if they are forced to be the default case. Default
yes.
controls if new files (ie. files that don't currently exist in the filesystem) which conform to 8.3 syntax,
that is all in upper case and of suitable length, are created upper case, or if they are forced to be the
default case. This option can be used with preserve case = yes to permit
long filenames to retain their case, while short names are lowercased. Default yes.
By default, Samba 3.0 has the same semantics as a Windows NT server, in that it is case insensitive but case preserving. As a special case for directories with large numbers of files, if the case options are set as follows, "case sensitive = yes", "case preserve = no", "short preserve case = no" then the "default case" option will be applied and will modify all filenames sent from the client when accessing this share.
There are a number of ways in which a user can connect to a service. The server uses the following steps in determining if it will allow a connection to a specified service. If all the steps fail, the connection request is rejected. However, if one of the steps succeeds, the following steps are not checked.
If the service is marked “guest only = yes” and the server is running with share-level security (“security = share”, steps 1 to 5 are skipped.
If the client has passed a username/password pair and that username/password pair is validated by the UNIX
system's password programs, the connection is made as that username. This includes the
\\server\service%username method of passing a username.
If the client has previously registered a username with the system and now supplies a correct password for that username, the connection is allowed.
The client's NetBIOS name and any previously used usernames are checked against the supplied password. If they match, the connection is allowed as the corresponding user.
If the client has previously validated a username/password pair with the server and the client has passed the validation token, that username is used.
If a user = field is given in the smb.conf file for the
service and the client has supplied a password, and that password matches (according to the UNIX system's
password checking) with one of the usernames from the user = field, the connection is made as
the username in the user = line. If one of the usernames in the user = list
begins with a @, that name expands to a list of names in the group of the same name.
If the service is a guest service, a connection is made as the username given in the guest account
= for the service, irrespective of the supplied password.
Starting with Samba version 3.2.0, the capability to
store Samba configuration in the registry is available.
The configuration is stored in the registry key
HKLM\Software\Samba\smbconf.
There are two levels of registry configuration:
Share definitions stored in registry are used.
This is triggered by setting the global
parameter registry shares
to “yes” in smb.conf.
The registry shares are loaded not at startup but on demand at runtime by smbd. Shares defined in smb.conf take priority over shares of the same name defined in registry.
Global smb.conf options stored in registry are used. This can be activated in two different ways:
Firstly, a registry only configuration is triggered by setting config backend = registry in the [global] section of smb.conf. This resets everything that has been read from config files to this point and reads the content of the global configuration section from the registry. This is the recommended method of using registry based configuration.
Secondly, a mixed configuration can be activated by a special new meaning of the parameter include = registry in the [global] section of smb.conf. This reads the global options from registry with the same priorities as for an include of a text file. This may be especially useful in cases where an initial configuration is needed to access the registry.
Activation of global registry options automatically activates registry shares. So in the registry only case, shares are loaded on demand only.
Note: To make registry-based configurations foolproof
at least to a certain extent, the use
of lock directory and
config backend
inside the registry configuration has been disabled:
Especially by changing the
lock directory inside the registry
configuration, one would create a broken setup where the daemons
do not see the configuration they loaded once it is active.
The registry configuration can be accessed with
tools like regedit or net (rpc)
registry in the key
HKLM\Software\Samba\smbconf.
More conveniently, the conf subcommand of the
net(8) utility
offers a dedicated interface to read and write the
registry based configuration locally, i.e. directly
accessing the database file, circumventing the
server.
This a full path name to a script called by smbd(8) that should stop a shutdown procedure issued by the shutdown script.
If the connected user posseses the SeRemoteShutdownPrivilege,
right, this command will be run as user.
Default: abort shutdown script = ""
Example: abort shutdown script = /sbin/shutdown -c
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 refersh. 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 = True
This parameter specifies what OS ACL semantics should be compatible with. Possible values are winnt for Windows NT 4, win2k for Windows 2000 and above and auto. If you specify auto, the value for this parameter will be based upon the version of the client. There should be no reason to change this parameter from the default.
Default: acl compatibility = Auto
Example: acl compatibility = win2k
In a POSIX filesystem, only the owner of a file or directory and the superuser can modify the permissions and ACLs on a file. If this parameter is set, then Samba overrides this restriction, and also allows the primary group owner of a file or directory to modify the permissions and ACLs on that file.
On a Windows server, groups may be the owner of a file or directory - thus allowing anyone in that group to modify the permissions on it. This allows the delegation of security controls on a point in the filesystem to the group owner of a directory and anything below it also owned by that group. This means there are multiple people with permissions to modify ACLs on a file or directory, easing managability.
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 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 is parameter has been marked deprecated in Samba 3.0.23. The same behavior is now
implemented by the dos filemode option.
Default: acl group control = no
This boolean parameter controls whether smbd(8)maps a POSIX ACE entry of "rwx" (read/write/execute), the maximum allowed POSIX permission set, into a Windows ACL of "FULL CONTROL". If this parameter is set to true any POSIX ACE entry of "rwx" will be returned in a Windows ACL as "FULL CONTROL", is this parameter is set to false any POSIX ACE entry of "rwx" will be returned as the specific Windows ACL bits representing read, write and execute.
Default: acl map full control = True
This is the full pathname to a script that will be run AS ROOT by smbd(8) when a new group is requested. It
will expand any %g to the group name passed. This script is only useful
for installations using the Windows NT domain administration tools. The script is free to create a group with
an arbitrary name to circumvent unix group name restrictions. In that case the script must print the numeric
gid of the created group on stdout.
Default: add group script =
Example: add group script = /usr/sbin/groupadd %g
This is the full pathname to a script that will be run by smbd(8) when a machine is added to Samba's domain and a Unix account matching the machine's name appended with a "$" does not already exist.
This option is very similar to the add user script, and likewise uses the %u substitution for the account name. Do not use the %m substitution.
Default: add machine script =
Example: add machine script = /usr/sbin/adduser -n -g machines -c Machine -d /var/lib/nobody -s /bin/false %u
Samba 3.0.23 introduced support for adding printer ports remotely using the Windows "Add Standard TCP/IP Port Wizard". This option defines an external program to be executed when smbd receives a request to add a new Port to the system. The script is passed two parameters:
port name
device URI
The deviceURI is in the for of socket://<hostname>[:<portnumber>] or lpd://<hostname>/<queuename>.
Default: add port command =
Example: add port command = /etc/samba/scripts/addport.sh
With the introduction of MS-RPC based printing support for Windows NT/2000 clients in Samba 2.2, The MS Add Printer Wizard (APW) icon is now also available in the "Printers..." folder displayed a share listing. The APW allows for printers to be add remotely to a Samba or Windows NT/2000 print server.
For a Samba host this means that the printer must be
physically added to the underlying printing system.
The addprinter command
defines a script to be run which
will perform the necessary operations for adding the printer
to the print system and to add the appropriate service definition
to the smb.conf file in order that it can be
shared by smbd(8).
The addprinter command is
automatically invoked with the following parameter (in
order):
printer name
share name
port name
driver name
location
Windows 9x driver location
All parameters are filled in from the PRINTER_INFO_2 structure sent by the Windows NT/2000 client with one exception. The "Windows 9x driver location" parameter is included for backwards compatibility only. The remaining fields in the structure are generated from answers to the APW questions.
Once the addprinter command has
been executed, smbd will reparse the
smb.conf to determine if the share defined by the APW
exists. If the sharename is still invalid, then smbd
will return an ACCESS_DENIED error to the client.
The addprinter command program
can output a single line of text,
which Samba will set as the port the new printer is connected to.
If this line isn't output, Samba won't reload its printer shares.
Default: addprinter command =
Example: addprinter command = /usr/bin/addprinter
Samba 2.2.0 introduced the ability to dynamically add and delete shares via the Windows NT 4.0 Server
Manager. The add share command is used to define an external program
or script which will add a new service definition to smb.conf. In order
to successfully execute the add share command, smbd requires that the administrator be connected using a root account (i.e. uid == 0).
If the connected account has SeDiskOperatorPrivilege, scripts defined in
change share parameter are executed as root.
When executed, smbd will automatically invoke the
add share command with five parameters.
configFile - the location of the global smb.conf file.
shareName - the name of the new share.
pathName - path to an **existing**
directory on disk.
comment - comment string to associate with the new
share.
max
connections
Number of maximum simultaneous connections to this
share.
This parameter is only used for add file shares. To add printer shares, see the addprinter command.
Default: add share command =
Example: add share command = /usr/local/bin/addshare
This is the full pathname to a script that will be run AS ROOT by smbd(8) under special circumstances described below.
Normally, a Samba server requires that UNIX users are created for all users accessing files on this server. For sites that use Windows NT account databases as their primary user database creating these users and keeping the user list in sync with the Windows NT PDC is an onerous task. This option allows smbd to create the required UNIX users ON DEMAND when a user accesses the Samba server.
In order to use this option, smbd(8) must NOT be set to
security = share and add user script
must be set to a full pathname for a script that will create a UNIX user given one argument of
%u, which expands into the UNIX user name to create.
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
Full path to the script that will be called when a user is added to a group using the Windows NT domain administration
tools. It will be run by smbd(8)
AS ROOT. Any %g will be replaced with the group name and
any %u will be replaced with the user name.
Note that the adduser command used in the example below does
not support the used syntax on all systems.
Default: add user to group script =
Example: add user to group script = /usr/sbin/adduser %u %g
If this parameter is set to yes for
a share, then the share will be an administrative share. The Administrative
Shares are the default network shares created by all Windows NT-based
operating systems. These are shares like C$, D$ or ADMIN$. The type of these
shares is STYPE_DISKTREE_HIDDEN.
See the section below on security for more information about this option.
Default: administrative share = no
This is a list of users who will be granted administrative privileges on the share. This means that they will do all file operations as the super-user (root).
You should use this option very carefully, as any user in this list will be able to do anything they like on the share, irrespective of file permissions.
This parameter will not work with the security = share in Samba 3.0. This is by design.
Default: admin users =
Example: admin users = jason
This parameter controls whether special AFS features are enabled
for this share. If enabled, it assumes that the directory exported via
the path parameter is a local AFS import. The
special AFS features include the attempt to hand-craft an AFS token
if you enabled --with-fake-kaserver in configure.
Default: afs share = no
If you are using the fake kaserver AFS feature, you might want to hand-craft the usernames you are creating tokens for. For example this is necessary if you have users from several domain in your AFS Protection Database. One possible scheme to code users as DOMAIN+User as it is done by winbind with the + as a separator.
The mapped user name must contain the cell name to log into, so without setting this parameter there will be no token.
Default: afs username map =
Example: afs username map = %u@afs.samba.org
If Samba has been built with asynchronous I/O support and this integer parameter is set to non-zero value, Samba will read from file asynchronously when size of request is bigger than this value. Note that it happens only for non-chained and non-chaining reads and when not using write cache.
Current implementation of asynchronous I/O in Samba 3.0 does support only up to 10 outstanding asynchronous requests, read and write combined.
Related command: write cache size
Related command: aio write size
Default: aio read size = 0
Example: aio read size = 16384
# Use asynchronous I/O for reads bigger than 16KB
request size
If Samba has been built with asynchronous I/O support and this integer parameter is set to non-zero value, Samba will write to file asynchronously when size of request is bigger than this value. Note that it happens only for non-chained and non-chaining reads and when not using write cache.
Current implementation of asynchronous I/O in Samba 3.0 does support only up to 10 outstanding asynchronous requests, read and write combined.
Related command: write cache size
Related command: aio read size
Default: aio write size = 0
Example: aio write size = 16384
# Use asynchronous I/O for writes bigger than 16KB
request size
This determines how Samba will use its algorithmic mapping from uids/gid to the RIDs needed to construct NT Security Identifiers.
Setting this option to a larger value could be useful to sites transitioning from WinNT and Win2k, as existing user and group rids would otherwise clash with sytem 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 allows an administrator to tune the allocation size reported to Windows clients. The default size of 1Mb generally results in improved Windows client performance. However, rounding the allocation size may cause difficulties for some applications, e.g. MS Visual Studio. If the MS Visual Studio compiler starts to crash with an internal error, set this parameter to zero for this share.
The integer parameter specifies the roundup size in bytes.
Default: allocation roundup size = 1048576
Example: allocation roundup size = 0
# (to disable roundups)
This option only takes effect when the security option is set to
server, domain or ads.
If it is set to no, then attempts to connect to a resource from
a domain or workgroup other than the one which smbd is running
in will fail, even if that domain is trusted by the remote server
doing the authentication.
This is useful if you only want your Samba server to serve resources to users in the domain it is a member of. As an example, suppose that there are two domains DOMA and DOMB. DOMB is trusted by DOMA, which contains the Samba server. Under normal circumstances, a user with an account in DOMB can then access the resources of a UNIX account with the same account name on the Samba server even if they do not have an account in DOMA. This can make implementing a security boundary difficult.
Default: allow trusted domains = yes
This specifies what type of server nmbd(8) will announce itself as, to a network neighborhood browse list. By default this is set to Windows NT. The valid options are : "NT Server" (which can also be written as "NT"), "NT Workstation", "Win95" or "WfW" meaning Windows NT Server, Windows NT Workstation, Windows 95 and Windows for Workgroups respectively. Do not change this parameter unless you have a specific need to stop Samba appearing as an NT server as this may prevent Samba servers from participating as browser servers correctly.
Default: announce as = NT Server
Example: announce as = Win95
This specifies the major and minor version numbers that nmbd will use when announcing itself as a server. The default is 4.9. Do not change this parameter unless you have a specific need to set a Samba server to be a downlevel server.
Default: announce version = 4.9
Example: announce version = 2.0
This option allows the administrator to chose what authentication methods smbd
will use when authenticating a user. This option defaults to sensible values based on security.
This should be considered a developer option and used only in rare circumstances. In the majority (if not all)
of production servers, the default setting should be adequate.
Each entry in the list attempts to authenticate the user in turn, until the user authenticates. In practice only one method will ever actually be able to complete the authentication.
Possible options include guest (anonymous access),
sam (lookups in local list of accounts based on netbios
name or domain name), winbind (relay authentication requests
for remote users through winbindd), ntdomain (pre-winbindd
method of authentication for remote domain users; deprecated in favour of winbind method),
trustdomain (authenticate trusted users by contacting the
remote DC directly from smbd; deprecated in favour of winbind method).
Default: auth methods =
Example: auth methods = guest sam winbind
This parameter lets you "turn off" a service. If
available = no, then ALL
attempts to connect to the service will fail. Such failures are
logged.
Default: available = yes
This global parameter allows the Samba admin to limit what interfaces on a machine will serve SMB requests. It affects file service smbd(8) and name service nmbd(8) in a slightly different ways.
For name service it causes nmbd to bind to ports 137 and 138 on the
interfaces listed in the interfaces parameter. nmbd
also binds to the "all addresses" interface (0.0.0.0) on ports 137 and 138 for the purposes of
reading broadcast messages. If this option is not set then nmbd will
service name requests on all of these sockets. If bind interfaces only is set then
nmbd will check the source address of any packets coming in on the
broadcast sockets and discard any that don't match the broadcast addresses of the interfaces in the
interfaces parameter list. As unicast packets are received on the other sockets it
allows nmbd to refuse to serve names to machines that send packets that
arrive through any interfaces not listed in the interfaces list. IP Source address
spoofing does defeat this simple check, however, so it must not be used seriously as a security feature for
nmbd.
For file service it causes smbd(8) to bind only to the interface list given in the interfaces parameter. This restricts the networks that smbd will
serve, to packets coming in on those interfaces. Note that you should not use this parameter for machines that
are serving PPP or other intermittent or non-broadcast network interfaces as it will not cope with
non-permanent interfaces.
If bind interfaces only is set and the network address 127.0.0.1 is not added to the interfaces parameter list smbpasswd(8) and swat(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 parameter, with remote machineremote
machine set to the IP name of the primary interface of the local host.
The swat status page tries to connect with smbd and nmbd at the address
127.0.0.1 to determine if they are running. Not adding 127.0.0.1
will cause smbd and nmbd to always show
"not running" even if they really are. This can prevent swat
from starting/stopping/restarting smbd and nmbd.
Default: bind interfaces only = no
This parameter controls the behavior of smbd(8) when given a request by a client to obtain a byte range lock on a region of an open file, and the request has a time limit associated with it.
If this parameter is set and the lock range requested cannot be immediately satisfied, samba will internally queue the lock request, and periodically attempt to obtain the lock until the timeout period expires.
If this parameter is set to no, then
samba will behave as previous versions of Samba would and
will fail the lock request immediately if the lock range
cannot be obtained.
Default: blocking locks = yes
This parameter controls the behavior of smbd(8) when reporting disk free sizes. By default, this reports a disk block size of 1024 bytes.
Changing this parameter may have some effect on the efficiency of client writes, this is not yet confirmed. This parameter was added to allow advanced administrators to change it (usually to a higher value) and test the effect it has on client write performance without re-compiling the code. As this is an experimental option it may be removed in a future release.
Changing this option does not change the disk free reporting size, just the block size unit reported to the client.
Default: block size = 1024
Example: block size = 4096
This controls whether this share is seen in the list of available shares in a net view and in the browse list.
Default: browseable = yes
This controls whether smbd(8) will serve a browse list to
a client doing a NetServerEnum call. Normally
set to yes. You should never need to change
this.
Default: browse list = yes
This parameter specifies whether Samba should reply to a client's file change notify requests.
You should never need to change this parameter
Default: change notify = yes
Samba 2.2.0 introduced the ability to dynamically add and delete shares via the Windows NT 4.0 Server
Manager. The change share command is used to define an external
program or script which will modify an existing service definition in smb.conf. In order to successfully execute the change
share command, smbd requires that the administrator be
connected using a root account (i.e. uid == 0).
If the connected account has SeDiskOperatorPrivilege, scripts defined in
change share parameter are executed as root.
When executed, smbd will automatically invoke the
change share command with five parameters.
configFile - the location
of the global smb.conf file.
shareName - the name of the new
share.
pathName - path to an **existing**
directory on disk.
comment - comment string to associate
with the new share.
max
connections
Number of maximum simultaneous connections to this
share.
This parameter is only used modify existing file shares definitions. To modify printer shares, use the "Printers..." folder as seen when browsing the Samba host.
Default: change share command =
Example: change share command = /usr/local/bin/addshare
The name of a program that can be used to check password complexity. The password is sent to the program's standard input.
The program must return 0 on a good password, or any other value if the password is bad. In case the password is considered weak (the program does not return 0) the user will be notified and the password change will fail.
Note: In the example directory is a sample program called crackcheck
that uses cracklib to check the password quality.
Default: check password script = Disabled
Example: check password script = check password script = /usr/local/sbin/crackcheck
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 it's 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 client ldap sasl wrapping defines whether ldap traffic will be signed or signed and encrypted (sealed). Possible values are plain, sign and seal.
The values sign and seal are only available if Samba has been compiled against a modern OpenLDAP version (2.3.x or higher).
This option is needed in the case of Domain Controllers enforcing
the usage of signed LDAP connections (e.g. Windows 2000 SP3 or higher).
LDAP sign and seal can be controlled with the registry key
"HKLM\System\CurrentControlSet\Services\
NTDS\Parameters\LDAPServerIntegrity"
on the Windows server side.
Depending on the used KRB5 library (MIT and older Heimdal versions) it is possible that the message "integrity only" is not supported. In this case, sign is just an alias for seal.
The default value is plain which is not irritable to KRB5 clock skew errors. That implies synchronizing the time with the KDC in the case of using sign or seal.
Default: client ldap sasl wrapping = plain
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. Many servers (including NT4 < SP4, Win9x and Samba 2.2) are not compatible with NTLMv2.
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 some sites (particularly those following 'best practice' security polices) only allow NTLMv2 responses, and not the weaker LM or NTLM.
Default: client ntlmv2 auth = no
Specifies whether a client should send a plaintext password if the server does not support encrypted passwords.
Default: client plaintext auth = no
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.
Default: client schannel = auto
Example: client schannel = yes
This controls whether the client offers or requires the server it talks to to use SMB signing. Possible values are auto, mandatory and disabled.
When set to auto, SMB signing is offered, but not enforced. When set to mandatory, SMB signing is required and if set to disabled, SMB signing is not offered either.
Default: client signing = auto
This variable controls whether Samba clients will try to use Simple and Protected NEGOciation (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.
Default: client use spnego = yes
With this parameter you can add additional addresses nmbd will register with a WINS server. These addresses are not necessarily present on all nodes simultaneously, but they will be registered with the WINS server so that clients can contact any of the nodes.
Default: cluster addresses =
Example: cluster addresses = 10.0.0.1 10.0.0.2 10.0.0.3
This parameter specifies whether Samba should contact ctdb for accessing its tdb files and use ctdb as a backend for its messaging backend.
Set this parameter to yes only if
you have a cluster setup with ctdb running.
Default: clustering = no
This is a text field that is seen next to a share
when a client does a queries the server, either via the network
neighborhood or via net view to list what shares
are available.
If you want to set the string that is displayed next to the machine name then see the server string parameter.
Default: comment =
# No comment
Example: comment = Fred's Files
This controls the backend for storing the configuration.
Possible values are file (the default)
and registry.
When config backend = registry
is encountered while loading smb.conf,
the configuration read so far is dropped and the global
options are read from registry instead. So this triggers a
registry only configuration. Share definitions are not read
immediately but instead registry
shares is set to yes.
Note: This option can not be set inside the registry configuration itself.
Default: config backend = file
Example: config backend = registry
This allows you to override the config file
to use, instead of the default (usually smb.conf).
There is a chicken and egg problem here as this option is set
in the config file!
For this reason, if the name of the config file has changed when the parameters are loaded then it will reload them from the new config file.
This option takes the usual substitutions, which can be very useful.
If the config file doesn't exist then it won't be loaded (allowing you to special case the config files of just a few clients).
No default
Example: config file = /usr/local/samba/lib/smb.conf.%m
This parameter allows you to "clone" service entries. The specified service is simply duplicated under the current service's name. Any parameters specified in the current section will override those in the section being copied.
This feature lets you set up a 'template' service and create similar services easily. Note that the service being copied must occur earlier in the configuration file than the service doing the copying.
Default: copy =
Example: copy = otherservice
When a file is created, the necessary permissions are calculated according to the mapping from DOS modes to UNIX permissions, and the resulting UNIX mode is then bit-wise 'AND'ed with this parameter. This parameter may be thought of as a bit-wise MASK for the UNIX modes of a file. Any bit not set here will be removed from the modes set on a file when it is created.
The default value of this parameter removes the group and other
write and execute bits from the UNIX modes.
Following this Samba will bit-wise 'OR' the UNIX mode created from this parameter with the value of the force create mode parameter which is set to 000 by default.
This parameter does not affect directory masks. See the parameter directory mask for details.
Note that this parameter does not apply to permissions set by Windows NT/2000 ACL editors. If the administrator wishes to enforce a mask on access control lists also, they need to set the security mask.
Default: create mask = 0744
Example: create mask = 0775
This stands for client-side caching policy, and specifies how clients capable of offline caching will cache the files in the share. The valid values are: manual, documents, programs, disable.
These values correspond to those used on Windows servers.
For example, shares containing roaming profiles can have offline caching disabled using csc policy = disable.
Default: csc policy = manual
Example: csc policy = programs
If you set clustering=yes,
you need to tell Samba where ctdbd listens on its unix domain
socket. The default path as of ctdb 1.0 is /tmp/ctdb.socket which
you have to explicitly set for Samba in smb.conf.
Default: ctdbd socket =
Example: ctdbd socket = /tmp/ctdb.socket
This parameter is only applicable if printing is
set to cups. Its value is a free form string of options
passed directly to the cups library.
You can pass any generic print option known to CUPS (as listed in the CUPS "Software Users' Manual"). You can also pass any printer specific option (as listed in "lpoptions -d printername -l") valid for the target queue. Multiple parameters should be space-delimited name/value pairs according to the PAPI text option ABNF specification. Collection values ("name={a=... b=... c=...}") are stored with the curley brackets intact.
You should set this parameter to raw if your CUPS server
error_log file contains messages such as
"Unsupported format 'application/octet-stream'" when printing from a Windows client
through Samba. It is no longer necessary to enable
system wide raw printing in /etc/cups/mime.{convs,types}.
Default: cups options = ""
Example: cups options = "raw media=a4"
This parameter is only applicable if printing is set to cups.
If set, this option overrides the ServerName option in the CUPS client.conf. This is
necessary if you have virtual samba servers that connect to different CUPS daemons.
Optionally, a port can be specified by separating the server name and port number with a colon. If no port was specified, the default port for IPP (631) will be used.
Default: cups server = ""
Example: cups server = mycupsserver
Example: cups server = mycupsserver:1631
The value of the parameter (a decimal integer) represents the number of minutes of inactivity before a connection is considered dead, and it is disconnected. The deadtime only takes effect if the number of open files is zero.
This is useful to stop a server's resources being exhausted by a large number of inactive connections.
Most clients have an auto-reconnect feature when a connection is broken so in most cases this parameter should be transparent to users.
Using this parameter with a timeout of a few minutes is recommended for most systems.
A deadtime of zero indicates that no auto-disconnection should be performed.
Default: deadtime = 0
Example: deadtime = 15
With this boolean parameter enabled, the debug class (DBGC_CLASS) will be displayed in the debug header.
For more information about currently available debug classes, see section about log level.
Default: debug class = no
Sometimes the timestamps in the log messages are needed with a resolution of higher that seconds, this boolean parameter adds microsecond resolution to the timestamp message header when turned on.
Note that the parameter debug timestamp must be on for this to have an effect.
Default: debug hires timestamp = no
When using only one log file for more then one forked smbd(8)-process there may be hard to follow which process outputs which message. This boolean parameter is adds the process-id to the timestamp message headers in the logfile when turned on.
Note that the parameter debug timestamp must be on for this to have an effect.
Default: debug pid = no
With this option enabled, the timestamp message header is prefixed to the debug message without the filename and function information that is included with the debug timestamp parameter. This gives timestamps to the messages without adding an additional line.
Note that this parameter overrides the debug timestamp parameter.
Default: debug prefix timestamp = no
Samba debug log messages are timestamped by default. If you are running at a high debug level these timestamps can be distracting. This boolean parameter allows timestamping to be turned off.
Default: debug timestamp = yes
Samba is sometimes run as root and sometime run as the connected user, this boolean parameter inserts the current euid, egid, uid and gid to the timestamp message headers in the log file if turned on.
Note that the parameter debug timestamp must be on for this to have an effect.
Default: debug uid = no
See the section on name mangling. Also note the short preserve case parameter.
Default: default case = lower
This parameter is only applicable to printable services. When smbd is serving Printer Drivers to Windows NT/2k/XP clients, each printer on the Samba server has a Device Mode which defines things such as paper size and orientation and duplex settings. The device mode can only correctly be generated by the printer driver itself (which can only be executed on a Win32 platform). Because smbd is unable to execute the driver code to generate the device mode, the default behavior is to set this field to NULL.
Most problems with serving printer drivers to Windows NT/2k/XP clients can be traced to a problem with the generated device mode. Certain drivers will do things such as crashing the client's Explorer.exe with a NULL devmode. However, other printer drivers can cause the client's spooler service (spoolsv.exe) to die if the devmode was not created by the driver itself (i.e. smbd generates a default devmode).
This parameter should be used with care and tested with the printer
driver in question. It is better to leave the device mode to NULL
and let the Windows client set the correct values. Because drivers do not
do this all the time, setting default devmode = yes
will instruct smbd to generate a default one.
For more information on Windows NT/2k printing and Device Modes, see the MSDN documentation.
Default: default devmode = yes
This parameter specifies the name of a service which will be connected to if the service actually requested cannot be found. Note that the square brackets are NOT given in the parameter value (see example below).
There is no default value for this parameter. If this parameter is not given, attempting to connect to a nonexistent service results in an error.
Typically the default service would be a guest ok, read-only service.
Also note that the apparent service name will be changed to equal
that of the requested service, this is very useful as it allows you to use macros like %S to make a wildcard service.
Note also that any "_" characters in the name of the service used in the default service will get mapped to a "/". This allows for interesting things.
Default: default service =
Example: default service = pub
Windows allows specifying how a file will be shared with other processes when it is opened. Sharing violations occur when a file is opened by a different process using options that violate the share settings specified by other processes. This parameter causes smbd to act as a Windows server does, and defer returning a "sharing violation" error message for up to one second, allowing the client to close the file causing the violation in the meantime.
UNIX by default does not have this behaviour.
There should be no reason to turn off this parameter, as it is designed to enable Samba to more correctly emulate Windows.
Default: defer sharing violations = True
This is the full pathname to a script that will
be run AS ROOT smbd(8) when a group is requested to be deleted.
It will expand any %g to the group name passed.
This script is only useful for installations using the Windows NT domain administration tools.
Default: delete group script =
With the introduction of MS-RPC based printer support for Windows NT/2000 clients in Samba 2.2, it is now possible to delete a printer at run time by issuing the DeletePrinter() RPC call.
For a Samba host this means that the printer must be
physically deleted from the underlying printing system. The
deleteprinter command defines a script to be run which
will perform the necessary operations for removing the printer
from the print system and from smb.conf.
The deleteprinter command is automatically called with only one parameter: printer name.
Once the deleteprinter command has
been executed, smbd will reparse the
smb.conf to check that the associated printer no longer exists.
If the sharename is still valid, then smbd
will return an ACCESS_DENIED error to the client.
Default: deleteprinter command =
Example: deleteprinter command = /usr/bin/removeprinter
This parameter allows readonly files to be deleted. This is not normal DOS semantics, but is allowed by UNIX.
This option may be useful for running applications such as rcs, where UNIX file ownership prevents changing file permissions, and DOS semantics prevent deletion of a read only file.
Default: delete readonly = no
Samba 2.2.0 introduced the ability to dynamically add and delete shares via the Windows NT 4.0 Server
Manager. The delete share command is used to define an external
program or script which will remove an existing service definition from
smb.conf. In order to successfully execute the
delete share command, smbd
requires that the administrator be connected using a root account (i.e. uid == 0).
If the connected account has SeDiskOperatorPrivilege, scripts defined in
change share parameter are executed as root.
When executed, smbd will automatically invoke the
delete share command with two parameters.
configFile - the location
of the global smb.conf file.
shareName - the name of
the existing service.
This parameter is only used to remove file shares. To delete printer shares, see the deleteprinter command.
Default: delete share command =
Example: delete share command = /usr/local/bin/delshare
Full path to the script that will be called when
a user is removed from a group using the Windows NT domain administration
tools. It will be run by smbd(8) AS ROOT.
Any %g will be replaced with the group name and
any %u will be replaced with the user name.
Default: delete user from group script =
Example: delete user from group script = /usr/sbin/deluser %u %g
This is the full pathname to a script that will be run by smbd(8) when managing users with remote RPC (NT) tools.
This script is called when a remote client removes a user
from the server, normally using 'User Manager for Domains' or
rpcclient.
This script should delete the given UNIX username.
Default: delete user script =
Example: delete user script = /usr/local/samba/bin/del_user %u
This option is used when Samba is attempting to
delete a directory that contains one or more vetoed directories
(see the veto files
option). If this option is set to no (the default) then if a vetoed
directory contains any non-vetoed files or directories then the
directory delete will fail. This is usually what you want.
If this option is set to yes, then Samba
will attempt to recursively delete any files and directories within
the vetoed directory. This can be useful for integration with file
serving systems such as NetAtalk which create meta-files within
directories you might normally veto DOS/Windows users from seeing
(e.g. .AppleDouble)
Setting delete veto files = yes allows these directories to be transparently deleted when the parent directory is deleted (so long as the user has permissions to do so).
Default: delete veto files = no
The dfree cache time should only be used on systems where a problem
occurs with the internal disk space calculations. This has been known to happen with Ultrix, but may occur
with other operating systems. The symptom that was seen was an error of "Abort Retry Ignore" at the
end of each directory listing.
This is a new parameter introduced in Samba version 3.0.21. It specifies in seconds the time that smbd will cache the output of a disk free query. If set to zero (the default) no caching is done. This allows a heavily loaded server to prevent rapid spawning of dfree command scripts increasing the load.
By default this parameter is zero, meaning no caching will be done.
No default
Example: dfree cache time = dfree cache time = 60
The dfree command setting should only be used on systems where a
problem occurs with the internal disk space calculations. This has been known to happen with Ultrix, but may
occur with other operating systems. The symptom that was seen was an error of "Abort Retry Ignore"
at the end of each directory listing.
This setting allows the replacement of the internal routines to calculate the total disk space and amount available with an external routine. The example below gives a possible script that might fulfill this function.
In Samba version 3.0.21 this parameter has been changed to be a per-share parameter, and in addition the parameter dfree cache time was added to allow the output of this script to be cached for systems under heavy load.
The external program will be passed a single parameter indicating a directory in the filesystem being queried.
This will typically consist of the string ./. The script should return
two integers in ASCII. The first should be the total disk space in blocks, and the second should be the number
of available blocks. An optional third return value can give the block size in bytes. The default blocksize is
1024 bytes.
Note: Your script should NOT be setuid or setgid and should be owned by (and writeable only by) root!
Where the script dfree (which must be made executable) could be:
#!/bin/sh
df $1 | tail -1 | awk '{print $(NF-4),$(NF-2)}'
or perhaps (on Sys V based systems):
#!/bin/sh
/usr/bin/df -k $1 | tail -1 | awk '{print $3" "$5}'
Note that you may have to replace the command names with full path names on some systems.
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
This parameter is the octal modes which are used when converting DOS modes to UNIX modes when creating UNIX directories.
When a directory is created, the necessary permissions are calculated according to the mapping from DOS modes to UNIX permissions, and the resulting UNIX mode is then bit-wise 'AND'ed with this parameter. This parameter may be thought of as a bit-wise MASK for the UNIX modes of a directory. Any bit not set here will be removed from the modes set on a directory when it is created.
The default value of this parameter removes the 'group' and 'other' write bits from the UNIX mode, allowing only the user who owns the directory to modify it.
Following this Samba will bit-wise 'OR' the UNIX mode created from this parameter with the value of the force directory mode parameter. This parameter is set to 000 by default (i.e. no extra mode bits are added).
Note that this parameter does not apply to permissions set by Windows NT/2000 ACL editors. If the administrator wishes to enforce a mask on access control lists also, they need to set the directory security mask.
Default: directory mask = 0755
Example: directory mask = 0775