mount.cifs — mount using the Common Internet File System (CIFS)
mount.cifs {service} {mount-point} [-o options]
This tool is part of the samba(7) suite.
mount.cifs mounts a Linux CIFS filesystem. It is usually invoked indirectly by the mount(8) 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.
The mount.cifs utility attaches the UNC name (exported network resource) to the local directory mount-point. 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.
Options to mount.cifs are specified as a comma-separated list of key=value pairs. It is possible to send options other than those listed here, assuming that cifs filesystem supports them. Unrecognized cifs mount options passed to the cifs vfs kernel code will be logged to the kernel log.
mount.cifs 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).
specifies the username to connect as. If this is not given, then the environment variable USER is used. This option can also take the form "user%password" or "user/workgroup" or "user/workgroup%password" to allow the password and workgroup to be specified as part of the username.
The cifs vfs accepts the parameter user=, or for users familiar with smbfs it accepts the longer form of the parameter username=. Similarly the longer smbfs style parameter names may be accepted as synonyms for the shorter cifs parameters pass=,dom= and cred=.
specifies the CIFS password. If this option is not given then the environment variable PASSWD is used. If the password is not specified directly or indirectly via an argument to mount mount.cifs will prompt for a password, unless the guest option is specified.
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) will be read correctly.
specifies a file that contains a username and/or password. The format of the file is:
username=value password=value
This is preferred over having passwords in plaintext in a shared file, such as /etc/fstab. Be sure to protect any credentials file properly.
sets the uid that will own all files on the mounted filesystem. It may be specified as either a username or a numeric uid. This parameter is ignored when the target server supports the CIFS Unix extensions.
sets the gid that will own all files on the mounted filesystem. It may be specified as either a groupname or a numeric gid. This parameter is ignored when the target server supports the CIFS Unix extensions.
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.
If the server does not support the CIFS Unix extensions this overrides the default file mode.
If the server does not support the CIFS Unix extensions this overrides the default mode for directories.
sets the destination host or IP address.
sets the domain (workgroup) of the user
don't prompt for a password
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.
mount read-only
mount read-write
default network read size
default network write size
The variable USER 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.
The variable PASSWD may contain the password of the person using the client.
The variable PASSWD_FILE may contain the pathname of a file to read the password from. A single line of input is read and used as the password.
This command may be used only by root, unless installed setuid, in which case the noeexec and nosuid mount flags are enabled.
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 /proc/fs/cifs are various configuration files and pseudo files which can display debug information. For more information see the kernel file fs/cifs/README.
Passwords and other options containing , can not be handled. For passwords an alternative way of passing them is in a credentials file or in the PASSWD environment.
The credentials file does not handle usernames or passwords with leading space.
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.
This man page is correct for version 1.0.6 of the cifs vfs filesystem (roughly Linux kernel 2.6.6).
Documentation/filesystems/cifs.txt and fs/cifs/README in the linux kernel source tree may contain additional options and information.
Steve French
The syntax and manpage were loosely based on that of smbmount. It was converted to Docbook/XML by Jelmer Vernooij.
The maintainer of the Linux cifs vfs and the userspace tool mount.cifs is Steve French. The Linux CIFS Mailing list is the preferred place to ask questions regarding these programs.