<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>mount.cifs</title><link rel="stylesheet" href="../samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.73.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en"><a name="mount.cifs.8"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>mount.cifs — mount using the Common Internet File System (CIFS)</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="literal">mount.cifs</code> {service} {mount-point} [-o options]</p></div></div><div class="refsect1" lang="en"><a name="id2518335"></a><h2>DESCRIPTION</h2><p>This tool is part of the <a class="citerefentry" href="samba.7.html"><span class="citerefentry"><span class="refentrytitle">samba</span>(7)</span></a> suite.</p><p>mount.cifs mounts a Linux CIFS filesystem. It
is usually invoked indirectly by
the <a class="citerefentry" href="mount.8.html"><span class="citerefentry"><span class="refentrytitle">mount</span>(8)</span></a> command when using the
"-t cifs" option. This command only works in Linux, and the kernel must
support the cifs filesystem. The CIFS protocol is the successor to the
SMB protocol and is supported by most Windows servers and many other
commercial servers and Network Attached Storage appliances as well as
by the popular Open Source server Samba.
</p><p>
The mount.cifs utility attaches the UNC name (exported network resource) to
the local directory <span class="emphasis"><em>mount-point</em></span>. It is possible to set the mode for mount.cifs to
setuid root to allow non-root users to mount shares to directories for which they
have write permission.
</p><p>
Options to <span class="emphasis"><em>mount.cifs</em></span> are specified as a comma-separated
list of key=value pairs. It is possible to send options other
than those listed here, assuming that the cifs filesystem kernel module (cifs.ko) supports them.
Unrecognized cifs mount options passed to the cifs vfs kernel code will be logged to the
kernel log.
</p><p><span class="emphasis"><em>mount.cifs</em></span> causes the cifs vfs to launch a thread named cifsd. After mounting it keeps running until
the mounted resource is unmounted (usually via the umount utility).
</p></div><div class="refsect1" lang="en"><a name="id2480179"></a><h2>OPTIONS</h2><div class="variablelist"><dl><dt><span class="term">user=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>specifies the username to connect as. If
this is not given, then the environment variable <span class="emphasis"><em>USER</em></span> is used. This option can also take the
form "user%password" or "workgroup/user" or
"workgroup/user%password" to allow the password and workgroup
to be specified as part of the username.
</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
The cifs vfs accepts the parameter <em class="parameter"><code>user=</code></em>, or for users familiar with smbfs it accepts the longer form of the parameter <em class="parameter"><code>username=</code></em>. Similarly the longer smbfs style parameter names may be accepted as synonyms for the shorter cifs parameters <em class="parameter"><code>pass=</code></em>,<em class="parameter"><code>dom=</code></em> and <em class="parameter"><code>cred=</code></em>.
</p></div></dd><dt><span class="term">password=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>specifies the CIFS password. If this
option is not given then the environment variable
<span class="emphasis"><em>PASSWD</em></span> is used. If the password is not specified
directly or indirectly via an argument to mount, <span class="emphasis"><em>mount.cifs</em></span> will prompt
for a password, unless the guest option is specified.
</p><p>Note that a password which contains the delimiter
character (i.e. a comma ',') will fail to be parsed correctly
on the command line. However, the same password defined
in the PASSWD environment variable or via a credentials file (see
below) or entered at the password prompt will be read correctly.
</p></dd><dt><span class="term">credentials=<em class="replaceable"><code>filename</code></em></span></dt><dd><p>
specifies a file that contains a username
and/or password. The format of the file is:
</p><pre class="programlisting">
username=<em class="replaceable"><code>value</code></em>
password=<em class="replaceable"><code>value</code></em>
</pre><p>
This is preferred over having passwords in plaintext in a
shared file, such as <code class="filename">/etc/fstab</code>. Be sure to protect any
credentials file properly.
</p></dd><dt><span class="term">uid=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>sets the uid that will own all files on
the mounted filesystem.
It may be specified as either a username or a numeric uid.
For mounts to servers which do support the CIFS Unix extensions,
such as a properly configured Samba server, the server provides
the uid, gid and mode so this parameter should not be
specified unless the server and client uid and gid
numbering differ. If the server and client are in the
same domain (e.g. running winbind or nss_ldap) and
the server supports the Unix Extensions then the uid
and gid can be retrieved from the server (and uid
and gid would not have to be specifed on the mount.
For servers which do not support the CIFS Unix
extensions, the default uid (and gid) returned on lookup
of existing files will be the uid (gid) of the person
who executed the mount (root, except when mount.cifs
is configured setuid for user mounts) unless the "uid="
(gid) mount option is specified. For the uid (gid) of newly
created files and directories, ie files created since
the last mount of the server share, the expected uid
(gid) is cached as long as the inode remains in
memory on the client. Also note that permission
checks (authorization checks) on accesses to a file occur
at the server, but there are cases in which an administrator
may want to restrict at the client as well. For those
servers which do not report a uid/gid owner
(such as Windows), permissions can also be checked at the
client, and a crude form of client side permission checking
can be enabled by specifying file_mode and dir_mode on
the client. Note that the mount.cifs helper must be
at version 1.10 or higher to support specifying the uid
(or gid) in non-numeric form.
</p></dd><dt><span class="term">gid=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>sets the gid that will own all files on
the mounted filesystem. It may be specified as either a groupname or a numeric
gid. For other considerations see the description of uid above.
</p></dd><dt><span class="term">port=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>sets the port number on the server to attempt to contact to negotiate
CIFS support. If the CIFS server is not listening on this port or
if it is not specified, the default ports will be tried i.e.
port 445 is tried and if no response then port 139 is tried.
</p></dd><dt><span class="term">servern=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>
Specify the server netbios name (RFC1001 name) to use
when attempting to setup a session to the server. Although
rarely needed for mounting to newer servers, this option
is needed for mounting to some older servers (such
as OS/2 or Windows 98 and Windows ME) since when connecting
over port 139 they, unlike most newer servers, do not
support a default server name. A server name can be up
to 15 characters long and is usually uppercased.
</p></dd><dt><span class="term">netbiosname=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>When mounting to servers via port 139, specifies the RFC1001
source name to use to represent the client netbios machine
name when doing the RFC1001 netbios session initialize.
</p></dd><dt><span class="term">file_mode=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>If the server does not support the CIFS Unix extensions this
overrides the default file mode.</p></dd><dt><span class="term">dir_mode=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>If the server does not support the CIFS Unix extensions this
overrides the default mode for directories. </p></dd><dt><span class="term">ip=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>sets the destination IP address. This option is set automatically if the server name portion of the requested UNC name can be resolved so rarely needs to be specified by the user.</p></dd><dt><span class="term">domain=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>sets the domain (workgroup) of the user </p></dd><dt><span class="term">guest</span></dt><dd><p>don't prompt for a password </p></dd><dt><span class="term">iocharset</span></dt><dd><p>Charset used to convert local path names to and from
Unicode. Unicode is used by default for network path
names if the server supports it. If iocharset is
not specified then the nls_default specified
during the local client kernel build will be used.
If server does not support Unicode, this parameter is
unused. </p></dd><dt><span class="term">ro</span></dt><dd><p>mount read-only</p></dd><dt><span class="term">rw</span></dt><dd><p>mount read-write</p></dd><dt><span class="term">setuids</span></dt><dd><p>If the CIFS Unix extensions are negotiated with the server
the client will attempt to set the effective uid and gid of
the local process on newly created files, directories, and
devices (create, mkdir, mknod). If the CIFS Unix Extensions
are not negotiated, for newly created files and directories
instead of using the default uid and gid specified on the
the mount, cache the new file's uid and gid locally which means
that the uid for the file can change when the inode is
reloaded (or the user remounts the share).</p></dd><dt><span class="term">nosetuids</span></dt><dd><p>The client will not attempt to set the uid and gid on
on newly created files, directories, and devices (create,
mkdir, mknod) which will result in the server setting the
uid and gid to the default (usually the server uid of the
user who mounted the share). Letting the server (rather than
the client) set the uid and gid is the default.If the CIFS
Unix Extensions are not negotiated then the uid and gid for
new files will appear to be the uid (gid) of the mounter or the
uid (gid) parameter specified on the mount.</p></dd><dt><span class="term">perm</span></dt><dd><p>Client does permission checks (vfs_permission check of uid
and gid of the file against the mode and desired operation),
Note that this is in addition to the normal ACL check on the
target machine done by the server software.
Client permission checking is enabled by default.</p></dd><dt><span class="term">noperm</span></dt><dd><p>Client does not do permission checks. This can expose
files on this mount to access by other users on the local
client system. It is typically only needed when the server
supports the CIFS Unix Extensions but the UIDs/GIDs on the
client and server system do not match closely enough to allow
access by the user doing the mount.
Note that this does not affect the normal ACL check on the
target machine done by the server software (of the server
ACL against the user name provided at mount time).</p></dd><dt><span class="term">directio</span></dt><dd><p>Do not do inode data caching on files opened on this mount.
This precludes mmaping files on this mount. In some cases
with fast networks and little or no caching benefits on the
client (e.g. when the application is doing large sequential
reads bigger than page size without rereading the same data)
this can provide better performance than the default
behavior which caches reads (readahead) and writes
(writebehind) through the local Linux client pagecache
if oplock (caching token) is granted and held. Note that
direct allows write operations larger than page size
to be sent to the server. On some kernels this requires the cifs.ko module
to be built with the CIFS_EXPERIMENTAL configure option.</p></dd><dt><span class="term">mapchars</span></dt><dd><p>Translate six of the seven reserved characters (not backslash, but including the colon, question mark, pipe, asterik, greater than and less than characters)
to the remap range (above 0xF000), which also
allows the CIFS client to recognize files created with
such characters by Windows's POSIX emulation. This can
also be useful when mounting to most versions of Samba
(which also forbids creating and opening files
whose names contain any of these seven characters).
This has no effect if the server does not support
Unicode on the wire.</p></dd><dt><span class="term">nomapchars</span></dt><dd><p>Do not translate any of these seven characters (default)</p></dd><dt><span class="term">intr</span></dt><dd><p>currently unimplemented</p></dd><dt><span class="term">nointr</span></dt><dd><p>(default) currently unimplemented </p></dd><dt><span class="term">hard</span></dt><dd><p>The program accessing a file on the cifs mounted file system will hang when the
server crashes.</p></dd><dt><span class="term">soft</span></dt><dd><p>(default) The program accessing a file on the cifs mounted file system will not hang when the server crashes and will return errors to the user application.</p></dd><dt><span class="term">noacl</span></dt><dd><p>Do not allow POSIX ACL operations even if server would support them.</p><p>
The CIFS client can get and set POSIX ACLs (getfacl, setfacl) to Samba servers
version 3.10 and later. Setting POSIX ACLs requires enabling both XATTR and
then POSIX support in the CIFS configuration options when building the cifs
module. POSIX ACL support can be disabled on a per mount basic by specifying
"noacl" on mount.</p></dd><dt><span class="term">nocase</span></dt><dd><p>Request case insensitive path name matching (case
sensitive is the default if the server suports it).
</p></dd><dt><span class="term">sec=</span></dt><dd><p>Security mode. Allowed values are:</p><div class="itemizedlist"><ul type="disc"><li><p>none attempt to connection as a null user (no name) </p></li><li><p>krb5 Use Kerberos version 5 authentication</p></li><li><p>krb5i Use Kerberos authentication and packet signing</p></li><li><p>ntlm Use NTLM password hashing (default)</p></li><li><p>ntlmi Use NTLM password hashing with signing (if
/proc/fs/cifs/PacketSigningEnabled on or if
server requires signing also can be the default)</p></li><li><p>ntlmv2 Use NTLMv2 password hashing</p></li><li><p>ntlmv2i Use NTLMv2 password hashing with packet signing</p></li></ul></div><p>[NB This [sec parameter] is under development and expected to be available in cifs kernel module 1.40 and later]
</p></dd><dt><span class="term">nobrl</span></dt><dd><p>Do not send byte range lock requests to the server.
This is necessary for certain applications that break
with cifs style mandatory byte range locks (and most
cifs servers do not yet support requesting advisory
byte range locks).
</p></dd><dt><span class="term">sfu</span></dt><dd><p>
When the CIFS Unix Extensions are not negotiated, attempt to
create device files and fifos in a format compatible with
Services for Unix (SFU). In addition retrieve bits 10-12
of the mode via the SETFILEBITS extended attribute (as
SFU does). In the future the bottom 9 bits of the mode
mode also will be emulated using queries of the security
descriptor (ACL). [NB: requires version 1.39 or later
of the CIFS VFS. To recognize symlinks and be able
to create symlinks in an SFU interoperable form
requires version 1.40 or later of the CIFS VFS kernel module.
</p></dd><dt><span class="term">serverino</span></dt><dd><p>Use inode numbers (unique persistent file identifiers)
returned by the server instead of automatically generating
temporary inode numbers on the client. Although server inode numbers
make it easier to spot hardlinked files (as they will have
the same inode numbers) and inode numbers may be persistent (which is
userful for some sofware),
the server does not guarantee that the inode numbers
are unique if multiple server side mounts are exported under a
single share (since inode numbers on the servers might not
be unique if multiple filesystems are mounted under the same
shared higher level directory). Note that not all
servers support returning server inode numbers, although
those that support the CIFS Unix Extensions, and Windows 2000 and
later servers typically do support this (although not necessarily
on every local server filesystem). Parameter has no effect if
the server lacks support for returning inode numbers or equivalent.
</p></dd><dt><span class="term">noserverino</span></dt><dd><p>client generates inode numbers (rather than using the actual one
from the server) by default.
</p></dd><dt><span class="term">nouser_xattr</span></dt><dd><p>(default) Do not allow getfattr/setfattr to get/set xattrs, even if server would support it otherwise. </p></dd><dt><span class="term">rsize=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>default network read size (usually 16K). The client currently
can not use rsize larger than CIFSMaxBufSize. CIFSMaxBufSize
defaults to 16K and may be changed (from 8K to the maximum
kmalloc size allowed by your kernel) at module install time
for cifs.ko. Setting CIFSMaxBufSize to a very large value
will cause cifs to use more memory and may reduce performance
in some cases. To use rsize greater than 127K (the original
cifs protocol maximum) also requires that the server support
a new Unix Capability flag (for very large read) which some
newer servers (e.g. Samba 3.0.26 or later) do. rsize can be
set from a minimum of 2048 to a maximum of 130048 (127K or
CIFSMaxBufSize, whichever is smaller)
</p></dd><dt><span class="term">wsize=<em class="replaceable"><code>arg</code></em></span></dt><dd><p>default network write size (default 57344)
maximum wsize currently allowed by CIFS is 57344 (fourteen
4096 byte pages)</p></dd><dt><span class="term">--verbose</span></dt><dd><p>Print additional debugging information for the mount. Note that this parameter must be specified before the -o. For example:</p><p>mount -t cifs //server/share /mnt --verbose -o user=username</p></dd></dl></div></div><div class="refsect1" lang="en"><a name="id2527776"></a><h2>SERVICE FORMATTING AND DELIMITERS</h2><p>
It's generally preferred to use forward slashes (/) as a delimiter in service names. They are considered to be the "universal delimiter" since they are generally not allowed to be embedded within path components on Windows machines and the client can convert them to blackslashes (\) unconditionally. Conversely, backslash characters are allowed by POSIX to be part of a path component, and can't be automatically converted in the same way.
</p><p>
mount.cifs will attempt to convert backslashes to forward slashes where it's able to do so, but it cannot do so in any path component following the sharename.
</p></div><div class="refsect1" lang="en"><a name="id2527800"></a><h2>ENVIRONMENT VARIABLES</h2><p>
The variable <span class="emphasis"><em>USER</em></span> may contain the username of the
person to be used to authenticate to the server.
The variable can be used to set both username and
password by using the format username%password.
</p><p>
The variable <span class="emphasis"><em>PASSWD</em></span> may contain the password of the
person using the client.
</p><p>
The variable <span class="emphasis"><em>PASSWD_FILE</em></span> may contain the pathname
of a file to read the password from. A single line of input is
read and used as the password.
</p></div><div class="refsect1" lang="en"><a name="id2527835"></a><h2>NOTES</h2><p>This command may be used only by root, unless installed setuid, in which case the noeexec and nosuid mount flags are enabled.</p></div><div class="refsect1" lang="en"><a name="id2527847"></a><h2>CONFIGURATION</h2><p>
The primary mechanism for making configuration changes and for reading
debug information for the cifs vfs is via the Linux /proc filesystem.
In the directory <code class="filename">/proc/fs/cifs</code> are various
configuration files and pseudo files which can display debug information.
There are additional startup options such as maximum buffer size and number
of buffers which only may be set when the kernel cifs vfs (cifs.ko module) is
loaded. These can be seen by running the modinfo utility against the file
cifs.ko which will list the options that may be passed to cifs during module
installation (device driver load).
For more information see the kernel file <code class="filename">fs/cifs/README</code>.
</p></div><div class="refsect1" lang="en"><a name="id2527879"></a><h2>BUGS</h2><p>Mounting using the CIFS URL specification is currently not supported.
</p><p>The credentials file does not handle usernames or passwords with
leading space.</p><p>
Note that the typical response to a bug report is a suggestion
to try the latest version first. So please try doing that first,
and always include which versions you use of relevant software
when reporting bugs (minimum: mount.cifs (try mount.cifs -V), kernel (see /proc/version) and
server type you are trying to contact.
</p></div><div class="refsect1" lang="en"><a name="id2527904"></a><h2>VERSION</h2><p>This man page is correct for version 1.52 of
the cifs vfs filesystem (roughly Linux kernel 2.6.24).</p></div><div class="refsect1" lang="en"><a name="id2527916"></a><h2>SEE ALSO</h2><p>
Documentation/filesystems/cifs.txt and fs/cifs/README in the linux kernel
source tree may contain additional options and information.
</p><p><a class="citerefentry" href="umount.cifs.8.html"><span class="citerefentry"><span class="refentrytitle">umount.cifs</span>(8)</span></a></p></div><div class="refsect1" lang="en"><a name="id2527937"></a><h2>AUTHOR</h2><p>Steve French</p><p>The syntax and manpage were loosely based on that of smbmount. It
was converted to Docbook/XML by Jelmer Vernooij.</p><p>The maintainer of the Linux cifs vfs and the userspace
tool <span class="emphasis"><em>mount.cifs</em></span> is <a class="ulink" href="mailto:sfrench@samba.org" target="_top">Steve French</a>.
The <a class="ulink" href="mailto:linux-cifs-client@lists.samba.org" target="_top">Linux CIFS Mailing list</a>
is the preferred place to ask questions regarding these programs.
</p></div></div></body></html>
