VFSTAB(5) File Formats and Configurations VFSTAB(5)


vfstab - table of file system defaults


The file /etc/vfstab describes defaults for each file system. The
information is stored in a table with the following column headings:

device device mount FS fsck mount mount
to mount to fsck point type pass at boot options

The fields in the table are space-separated and show the resource name
(device to mount), the raw device to fsck (device to fsck), the default
mount directory (mount point), the name of the file system type (FS type),
the number used by fsck(8) to decide whether to check the file system
automatically (fsck pass), whether the file system should be mounted
automatically by mountall(8) (mount at boot), and the file system mount
options (mount options). See respective mount file system man page below
in SEE ALSO for mount options. A `-' is used to indicate no entry in a
field. This may be used when a field does not apply to the resource being

The getvfsent(3C) family of routines is used to read /etc/vfstab. There
are currently no library routines to automate the writing of /etc/vfstab.

/etc/vfstab can be used to specify swap areas. An entry so specified,
(which can be a file or a device), will automatically be added as a swap
area by the /sbin/swapadd script when the system boots. To specify a swap
area, the device-to-mount field contains the name of the swap file or
device, the FS-type is "swap", mount-at-boot is "no" and all other fields
have no entry.


The following are /etc/vfstab entries for various file system types
supported in illumos.

Example 1 NFS and UFS Mounts

The following entry invokes NFS to automatically mount the directory
/usr/local of the server example1 on the client's /usr/local directory with
read-only permission:

example1:/usr/local - /usr/local nfs - yes ro

The following example assumes a small departmental mail setup, in which
clients mount /var/mail from a server mailsvr. The following entry would
be listed in each client's /etc/vfstab:

mailsvr:/var/mail - /var/mail nfs - yes intr,bg

The following is an example for a UFS file system in which logging is

/dev/dsk/c2t10d0s0 /dev/rdsk/c2t10d0s0 /export/local ufs 3 yes logging

See mount_nfs(8) for a description of NFS mount options and mount_ufs(8)
for a description of UFS options.

Example 2 pcfs Mounts

The following example mounts a pcfs file system on a fixed hard disk on an
x86 machine:

/dev/dsk/c1t2d0p0:c - /win98 pcfs - yes -

The example below mounts a Jaz drive on a SPARC machine. Normally, the
volume management software handles mounting of removable media, obviating a
vfstab entry. Specifying a device that supports removable media in
/etc/vfstab with set the mount-at-boot field to "no" (as shown below)
disables the automatic handling of that device. Such an entry presumes you
are not running volume management software.

/dev/dsk/c1t2d0s2:c - /jaz pcfs - no -

For removable media on a SPARC machine, the convention for the slice
portion of the disk identifier is to specify s2, which stands for the
entire medium.

For pcfs file systems on x86 machines, note that the disk identifier uses a
p (p0) and a logical drive (c, in the /win98 example above) for a pcfs
logical drive. See mount_pcfs(8) for syntax for pcfs logical drives and
for pcfs-specific mount options.

Example 3 loopback File System Mount

The following is an example of mounting a loopback (lofs) file system:

/export/test - /opt/test lofs - yes -
See lofs(4FS) for an overview of the loopback file system.


getvfsent(3C), fsck(8), mount(8), mount_hsfs(8), mount_nfs(8),
mount_tmpfs(8), mount_ufs(8), swap(8)

illumos January 16, 2022 illumos