System Administration Guide: Devices and File Systems

Field Descriptions for the /etc/vfstab File

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

Table 18–3 Field Descriptions for the /etc/vfstab File

Field Name 


device to mount

This field identifies one of the following: 

  • 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: IP Services.

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

  • A directory for a virtual file system.

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 field determines the raw interface that is used by the fsck command. 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

Identifies the type of file system. 

fsck pass

The pass number used by the fsck command to decide whether to check a UFS file system. When the field contains a dash (-), the file system is not checked. Currently, the fsck pass value in the /etc/vfstab file is ignored during the boot process.

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

All UFS 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 the fsck command is run on multiple UFS file systems that have fsck pass values greater than 1 and the preen option (-o p) is used, the fsck command 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.

mount at boot

Set to yes or no for whether the file system should be automatically mounted by the mountall command 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 for mounting the file system. Use a dash (-) to indicate no options. For a list of commonly used mount options, see Table 18–2.

Note –

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