/etc/vfstab tutorial
The vfstab file is used by the operating system to define default filesystems.
The vfstab file consists of seven "columns" or fields, separated by tabs
or spaces. In order to keep things consistent, we will use tabs to separate
our fields. The vfstab file is read at startup or when you run the mountall
command.
A typical vfstab file will look like this:
========================
#device device mount FS fsck mount mount
#to mount to fsck point type pass at boot options
#
#/dev/dsk/c1d0s2 /dev/rdsk/c1d0s2 /usr ufs 1 yes -
fd - /dev/fd fd - no -
/proc - /proc proc - no -
/dev/dsk/c0t0d0s1 - - swap - no -
/dev/dsk/c0t0d0s0 /dev/rdsk/c0t0d0s0 / ufs 1 no
-
swap - /tmp tmpfs - yes -
========================
The first thing you will probably notice is that the fields do not line up
neatly under the "column headings." The file appears to makes absolutely
no sense. However, the computer does not need to see neat little rows in
order to make sense of the file. The computer tells the difference between
fields by looking for the whitespace between fields. The same file as above
edited for ease of viewing by a human would appear as the following:
========================
#device device mount FS fsck mount mount
#to mount to fsck point type pass at boot options
#
#/dev/dsk/c1d0s2 /dev/rdsk/c1d0s2 /usr ufs 1 yes -
fd - /dev/fd fd - no -
/proc - /proc proc - no -
/dev/dsk/c0t0d0s1 - - swap - no -
/dev/dsk/c0t0d0s0 /dev/rdsk/c0t0d0s0 / ufs 1 no -
swap - /tmp tmpfs - yes -
========================
You will also notice that fields that do not have information in them are
not left blank. Instead a hypen is used to let the computer know that the
information is not necessary. Let's take a closer look at what each column
means.
++++++++++++++++++++++++
device to mount: the name of the resource to be mounted (i.e. /dev/dsk/c0t1d0s0)
device to fsck: the raw device to be checked by fsck (i.e. /dev/rdsk/c0t1d0s0)
mount point: the name of the directory where the device will be attached
to the filesystem (i.e. /disk2)
FS type: the kind of filesystem on the device (i.e. ufs, tmpfs)
fsck pass: a numeric value used by fsck to determine whether to check
the filesystem or not. To be on the safe side, put a 1 in this field unless
it is a read-only filesystem, in which case you should put a hyphen. If you
want the long explaination, see Table 39-3 on this page: http://docs.sun.com/db/doc/805-7228/6j6q7uf0g?a=view
mount at boot: this field is used to determine whether the file system
will be automatically mounted at boot time; can either be yes or no; usually,
entries specifying devices with removable media will take an 'no' in this
field
mount options: allows you to set special FS-specific mount options,
such as read-only, logging, etc. For more information on special mount options
see man pages for the following: mount_cachefs, mount_hsfs, mount_nfs, mount_pcfs,
mount_tmpfs or mount_ufs
++++++++++++++++++++++++
For a walkthrough on using the vfstab file to automount a slice at startup,
see our page on automounting.