mount Command

Purpose

Makes a file system available for use.

Syntax

mount [ -f ] [ -n node ] [ -o options ] [ -p ] [ -r ] [ -v vfsname ] [ -F AltFSfile ] [ -t type | [ device | node:directory ] directory | all | -a ] [-V [generic_options] special_mount_points ]

Description

The mount command instructs the operating system to make a file system available for use at a specified location (the mount point). In addition, you can use the mount command to build other file trees made up of directory and file mounts. The mount command mounts a file system expressed as a device using the device or node:directory parameter on the directory specified by the directory parameter. After the mount command has finished, the directory specified becomes the root directory of the newly mounted file system.

Only users with root authority or are members of the system group and have write access to the mount point can issue file or directory mounts. The file or directory may be a symbolic link. The mount command uses the real user ID, not the effective user ID, to determine if the user has appropriate access. System group members can issue device mounts, provided they have write access to the mount point and those mounts specified in the /etc/file systems file. Users with root user authority can issue any mount command.

Users can mount a device provided they belong to the system group and have appropriate access. When mounting a device, the mount command uses the device parameter as the name of the block device and the directory parameter as the directory on which to mount the file system.

If you enter the mount command without flags, the command displays the following information for the mounted file systems:

• the node (if the mount is remote)
• the object mounted
• the mount point
• the virtual-file-system type
• the time mounted
• any mount options

If you specify only the directory or node:directory parameter, the mount command takes it to be the name of the directory or file on which a file system, directory, or file is usually mounted (as defined in the /etc/file systems file). The mount command looks up the associated device, directory, or file and mounts it. This is the most convenient way of using the mount command, because it does not require you to remember what is normally mounted on a directory or file. You can also specify only the device. In this case, the command obtains the mount point from the /etc/file systems file.

The /etc/file systems file should include a stanza for each mountable file system, directory, or file. This stanza should specify at least the name of the file system and either the device on which it resides or the directory name. If the stanza includes a mount attribute, the mount command uses the associated values. It recognizes five values for the mount attributes: automatic, true, false, removable, and readonly.

The mount all command causes all file systems with the mount=true attribute to be mounted in their normal places. This command is typically used during system initialization, and the corresponding mount operations are referred to as automatic mount operations.

By default, the mount command runs the wlmcntrl command to refresh the current assignment rules in the kernel after mounting the file system. In some situations (such as when many file systems are mounted at once, or when a rule for an inaccessible remote mount is present in the workload manager configuration), calling wlmcntrl automatically after mount might be undesirable.

If you wish to override this behavior, set the environment variable MOUNT_WLMCNTRL_SELFMANAGE to any value. This will avoid calling the wlmcntrl command during the mount operation. You must manually run wlmcntrl -u -d "" to refresh the current assignment rules in the kernel. For more information, see wlmcntrl command.

Using mount on a JFS2 File System

The mount command can also be used to access a snapshot of a JFS2 file system as a directory tree. The snapshot on device is mounted read-only at directory. A snapshot can only be mounted once. When mounting a JFS2 file system with snapshots, the snapshots are activated.

You can use the System Management Interface Tool (SMIT) smit mount fast path to run this command.

Flags

File System Specific Options

NFS Specific Options

CacheFS Specific Options

The CacheFS-specific version of the mount command mounts a cached file system; if necessary, it NFS-mounts its back file system. It also provides a number of CacheFS-specific options for controlling the caching process.

To mount a CacheFS file system, use the mount command with the -V flag followed by the argument. The following mount flags are available.

Server Message Block (SMB) client file system specific options

If the options that are used with the mount command (pver, signing, secure_negotiate, or encryption) are unspecified by using the -o flag, the default values for the mount command options are initialized by using the new values of the kernel tunable parameters (smbc_protocol_version, smbc_signing, smbc_secure_negotiate, smbc_encryption). The kernel tunable parameters are initialized from tunable parameters defined in the smbctune.conf file. These parameters can also be modified by using the smbctune command.

Security

Examples

1. To list the mounted file systems, enter the following command:

   mount

   This command produces output similar to the following:

   node   mounted          mounted over  vfs    date              options   
   ----   -------          ------------ ---  ------------   -------------------
          /dev/hd0         /            jfs   Dec 17 08:04   rw, log  =/dev/hd8
          /dev/hd3         /tmp         jfs   Dec 17 08:04   rw, log  =/dev/hd8
          /dev/hd1         /home        jfs   Dec 17 08:06   rw, log  =/dev/hd8
          /dev/hd2         /usr         jfs   Dec 17 08:06   rw, log  =/dev/hd8
   sue    /home/local/src  /usr/code    nfs   Dec 17 08:06   ro, log  =/dev/hd8

   For each file system, the mount command lists the node name, the device name, the name under which it is mounted, the virtual-file-system type, the date and time it was mounted, and its options.
2. To mount all default file systems, enter the following command:
   mount all
   This command sequence mounts all standard file systems in the /etc/file systems file marked by the mount=true attribute.
3. To mount a remote directory, enter the following command:
   mount -n nodeA /home/tom.remote /home/tom.local
   This command sequence mounts the /home/tom.remote directory located on nodeA onto the local /home/tom.local directory. It assumes the default VfsName parameter=remote, which must be defined in the /etc/vfs file.
4. To mount a file or directory from the /etc/file systems file with a specific type, enter the following command:
   mount -t remote
   This command sequence mounts all files or directories in the /etc/file systems file that have a stanza that contains the type=remote attribute.
5. To CacheFS-mount the file system which is already NFS-mounted on /usr/abc, enter the following command:

   mount -V cachefs -o backfstype=nfs,backpath=/usr/abc,
   cachedir=/cache1 server1:/user2 /xyz

   The lines similar to the following appear in the /etc/mnttab file after the mount command is executed:

   server1:/user2 /usr/abc nfs
   /usr/abc /cache1/xyz cachefs backfstype=nfs

6. To mount a snapshot, enter the following command:

   mount -o snapshot /dev/snapsb /home/janet/snapsb

   This command mounts the snapshot contained on the /dev/snapsb device onto the /home/janet/snapsb directory.
7. To mount a file system and create a snapshot, enter the following command:

   mount -o snapto=/dev/snapsb /dev/sb /home/janet/sb

   This command mounts the file system contained on the /dev/sbdevice onto the /home/janet/sb directory and creates a snapshot for the file system on the /dev/snapsbdevice.
8. To access files on an SMB server as a local file system, enter the following command:

   mount -v cifs -n pezman/user1/pass1 -o uid=201,fmode=750 /home /mnt

9. To mount an SMB client file system as a local mount point, enter the following command:

   mount -v smbc -n llm140.xyz.com/cec102usr1/Passw0rd     \
   -o wrkgrp=SMB_21.FVT,port=445,signing=required /some_share /mnt

   Where, llm140.xyz.com is the Windows server, cec102usr1 is the Kerberos user name, Passw0rd is the password of the Kerberos user, SMB_21.FVT is the workgroup, some_share is the share point on the Windows system, and /mnt is the local mount point.
10. To remount the mounted read-only JFS2 file system to a read-write file system, enter the following command:

    mount –o remount,rw fsname

11. To mount all on a file /tmp/fs1 of an alternate file system, enter the following command:

    mount -F /tmp/fs1 all

Files