System Administration Guide, Volume 1

Mounting File Systems (/etc/vfstab File)

The /etc/vfstab Field Descriptions

An entry in the /etc/vfstab file has seven fields, which are described in the table below.

Table 36-4 /etc/vfstab Field Descriptions

Field Name 

Description 

device to mount

  • The block device name for a local UFS file system (for example, /dev/dsk/c0t0d0s0).

  • The resource name for a remote file system (for example, myserver:/export/home). For more information about NFS, see System Administration Guide, Volume 3.

  • The block device name of the slice on which to swap (for example, /dev/dsk/c0t3d0s1).

  • The /proc directory for the proc file system type.

device to fsck

The raw (character) device name that corresponds to the UFS file system identified by the device to mount field (for example, /dev/rdsk/c0t0d0s0). This determines the raw interface that is used by fsck. Use a dash (-) when there is no applicable device, such as for a read-only file system or a remote file system.

mount point

Identifies where to mount the file system (for example, /usr).

 

FS type

The type of file system identified by the device to mount field.

fsck pass

The pass number used by fsck to decide whether to check a file system. When the field contains a dash (-), the file system is not checked.

When the field contains a zero, UFS file systems are not checked but non-UFS file systems are checked. When the field contains a value greater than zero, the file system is always checked.  

All file systems with a value of 1 in this field, are checked one at a time in the order they appear in the vfstab file. When fsck is run on multiple UFS file systems that have fsck pass values greater than one and the preen option (-o p) is used, fsck automatically checks the file systems on different disks in parallel to maximize efficiency. Otherwise, the value of the pass number does not have any effect.

The fsck pass field does not explicitly specify the order in which file systems are checked, other than as described above.

mount at boot

Set to yes or no for whether the file system should be automatically mounted by mountall when the system is booted. Note that this field has nothing to do with AutoFS. The root (/), /usr and /var file systems are not mounted from the vfstab file initially. This field should always be set to no for these file systems and for virtual file systems such as /proc and /dev/fd.

mount options

A list of comma-separated options (with no spaces) that are used in mounting the file system. Use a dash (-) to indicate no options. See Table 36-3 for a list of commonly used mount options.


Note -

You must have an entry in each field in the /etc/vfstab file. If there is no value for the field, be sure to enter a dash (-), otherwise the system might not boot successfully. Similarly, white space should not be used in a field value.


How to Add an Entry to the /etc/vfstab File

  1. Become superuser.

    Also, there must be a mount point on the local system to mount a file system. A mount point is a directory to which the mounted file system is attached.

  2. Edit the /etc/vfstab file and add an entry.


    Note -

    Since the root (/) file system is mounted read-only by the kernel during the boot process, only the remount option (and options that can be used in conjunction with remount) affect the root (/) entry in the /etc/vfstab file.


    See Table 36-4 for detailed information about the /etc/vfstab field entries. Make sure that you:

    • Separate each field with white space (a space or a tab).

    • Enter a dash (-) if a field has no contents.

  3. Save the changes.

Examples--Adding an Entry to the /etc/vfstab File

The following example mounts the disk slice /dev/dsk/c0t3d0s7 as a UFS file system attached to the mount point directory /files1 with the default mount options (read/write). It specifies the raw character device /dev/rdsk/c0t3d0s7 as the device to fsck. The fsck pass value of 2 means that the file system will be checked, but not sequentially.


#device           device             mount    FS       fsck   mount    mount
#to mount         to fsck            point    type     pass   at boot  options
#
/dev/dsk/c0t3d0s7 /dev/rdsk/c0t3d0s7 /files1  ufs      2      yes       -

The following example mounts the directory /export/man from the system pluto as an NFS file system on mount point /usr/man. It does not specify a device to fsck or a fsck pass because it's an NFS file system. In this example, mount options are ro (read-only) and soft. For greater reliability, specify the hard mount option for read/write NFS file systems.


#device           device             mount    FS       fsck   mount    mount
#to mount         to fsck            point    type     pass   at boot  options
pluto:/export/man   -                /usr/man nfs      -      yes       ro,soft

The following example mounts the root (/) file system on a loopback mount point named /tmp/newroot. It specifies yes for mount at boot, no device to fsck, and no fsck pass number. LOFS file systems must always be mounted after the file systems used to make up the LOFS file system.


#device           device             mount    FS       fsck   mount    mount
#to mount         to fsck            point    type     pass   at boot  options
#
/                   -                /tmp/newroot lofs -      yes       -                   

How to Mount a File System (/etc/vfstab File)

  1. Become superuser.

    Also, there must be a mount point on the local system to mount a file system. A mount point is a directory to which the mounted file system is attached.

  2. Mount a file system listed in the /etc/vfstab file.


    # mount mount-point
    

    mount-point

    Specifies an entry in the mount point or device to mount field in the /etc/vfstab file. It is usually easier to specify the mount point.

Example--Mounting a File System (/etc/vfstab File)

The following example mounts the /usr/dist file system listed in the /etc/vfstab file.


# mount /usr/dist

How to Mount All File Systems (/etc/vfstab File)

  1. Become superuser.

    Also, there must be a mount point on the local system to mount a file system. A mount point is a directory to which the mounted file system is attached.

  2. Mount the file systems listed in the /etc/vfstab file.


    # mountall [-l | -r] [-F fstype]

    If no options are specified, all file systems listed in the /etc/vfstab file with yes in the mount at boot field are mounted.

    -l

    Mounts all the local file systems listed in the /etc/vfstab file with yes in the mount at boot field.

    -r

    Mounts all the remote file systems listed in the /etc/vfstab file with yes in the mount at boot field.

    -F fstype

    Mounts all file systems of the specified type listed in the /etc/vfstab file with yes in the mount at boot field.

    All the file systems with a device to fsck entry are checked and fixed, if necessary, before mounting.

Examples--Mounting All File Systems (/etc/vfstab File)

The following example shows the messages displayed if file systems are already mounted when you use the mountall command.


# mountall
/dev/rdsk/c0t0d0s7 already mounted
mount: /tmp already mounted
mount: /dev/dsk/c0t0d0s7 is already mounted, /export/home is busy,
        or the allowable number of mount points has been exceeded

The following example mounts all the local systems listed in the /etc/vfstab file.


# mountall -l
# mount
/ on /dev/dsk/c0t0d0s0 read/write/setuid/intr/largefiles/onerror=panic on ...
/usr on /dev/dsk/c0t0d0s6 read/write/setuid/intr/largefiles/onerror=panic on ...
/proc on /proc read/write/setuid on Fri Sep 10 16:09:48 1999
/dev/fd on fd read/write/setuid on Fri Sep 10 16:09:51 1999
/etc/mnttab on mnttab read/write/setuid on Fri Sep 10 16:10:06 1999
/var/run on swap read/write/setuid on Fri Sep 10 16:10:06 1999
/tmp on swap read/write/setuid on Fri Sep 10 16:10:09 1999
/export/home on /dev/dsk/c0t0d0s7 read/write/setuid/intr/largefiles/onerror=panic on ...

The following example mounts all the remote file systems listed in the /etc/vfstab file.


# mountall -r
# mount
/ on /dev/dsk/c0t0d0s0 read/write/setuid/intr/largefiles/onerror=panic on ...
/usr on /dev/dsk/c0t0d0s6 read/write/setuid/intr/largefiles/onerror=panic on ...
/proc on /proc read/write/setuid on Fri Sep 10 16:09:48 1999
/dev/fd on fd read/write/setuid on Fri Sep 10 16:09:51 1999
/etc/mnttab on mnttab read/write/setuid on Fri Sep 10 16:10:06 1999
/var/run on swap read/write/setuid on Fri Sep 10 16:10:06 1999
/tmp on swap read/write/setuid on Fri Sep 10 16:10:09 1999
/export/home on /dev/dsk/c0t0d0s7 read/write/setuid/intr/largefiles/onerror=panic on ...
/usr/dist on mars:/usr/dist remote/read/write/setuid on Tue Sep 14 15:32:18 1999