The  file fstab contains descriptive information about the various file
       systems.  fstab is only read by programs, and not written;  it  is  the
       duty  of  the system administrator to properly create and maintain this
       file.  Each filesystem is described on a separate line; fields on  each
       line are separated by tabs or spaces.  Lines starting with '#' are com-
       ments, blank lines are ignored. The order of records in fstab is impor-
       tant  because  fsck(8),  mount(8),  and  umount(8) sequentially iterate
       through fstab doing their thing, though at boot  time  mountall(8)  may
       process the file out-of-order when it believes it is safe to do so.

       The first field (fs_spec).
              This field describes the block special device or remote filesys-
              tem to be mounted.

              For ordinary mounts it will hold (a link  to)  a  block  special
              device  node  (as  created  by  mknod(8))  for  the device to be
              mounted, like `/dev/cdrom' or `/dev/sdb7'.  For NFS  mounts  one
              will have <host>:<dir>, e.g., `knuth.aeb.nl:/'.  For procfs, use

              Instead of giving the device explicitly, one  may  indicate  the
              (ext2  or  xfs)  filesystem that is to be mounted by its UUID or
              volume  label  (cf.   e2label(8)   or   xfs_admin(8)),   writing
              LABEL=<label>    or    UUID=<uuid>,    e.g.,   `LABEL=Boot'   or
              `UUID=3e6be9de-8139-11d1-9106-a43f08d823a6'.  This will make the
              system  more  robust: adding or removing a SCSI disk changes the
              disk device name but not the filesystem volume label.

              Note that mount(8) uses UUIDs as strings. The string representa-
              tion of the UUID should be based on lower case characters.

       The second field (fs_file).
              This  field  describes  the mount point for the filesystem.  For
              swap partitions, this field should be specified  as  `none'.  If
              the name of the mount point contains spaces these can be escaped
              as `\040'.

       The third field (fs_vfstype).
              This field describes the type of the filesystem.  Linux supports
              lots  of  filesystem  types,  such  as adfs, affs, autofs, coda,
              coherent, cramfs, devpts, efs, ext2, ext3, hfs,  hpfs,  iso9660,
              jfs,  minix,  msdos,  ncpfs,  nfs,  ntfs,  proc, qnx4, reiserfs,
              romfs, smbfs, sysv, tmpfs, udf, ufs, umsdos, vfat,  xenix,  xfs,
              and possibly others. For more details, see mount(8).

              For  the  filesystems currently supported by the running kernel,
              see /proc/filesystems.

              An entry swap denotes a file or partition to be used  for  swap-

              It is formatted as a comma separated list of options.   It  con-
              tains  at  least  the  type of mount plus any additional options
              appropriate to the filesystem type.  For  documentation  on  the
              available mount options, see mount(8).  For documentation on the
              available swap options, see swapon(8).

              Basic file system independent options are:

                     use default options: rw, suid, dev, exec,  auto,  nouser,
                     and async.

              noauto do  not  mount  when  "mount  -a" is given (e.g., at boot

              user   allow a user to mount

              owner  allow device owner to mount

                     for use by fstab-maintaining programs

              nofail do not report errors for  this  device  if  it  does  not

       The  mountall(8) program that mounts filesystem during boot also recog-
       nises additional options that the  ordinary  mount(8)  tool  does  not.
       These  are:  ``bootwait''  which  can  be applied to remote filesystems
       mounted outside of /usr or /var, without which  mountall(8)  would  not
       hold up the boot for these; ``nobootwait'' which can be applied to non-
       remote filesystems to explicitly instruct mountall(8) not  to  hold  up
       the boot for them; ``optional'' which causes the entry to be ignored if
       the filesystem type is not known  at  boot  time;  and  ``showthrough''
       which  permits  a mountpoint to be mounted before its parent mountpoint
       (this latter should be used carefully, as it can cause boot hangs).

       The fifth field (fs_freq).
              This field is used for these filesystems by the dump(8)  command
              to  determine which filesystems need to be dumped.  If the fifth
              field is not present, a value of zero is returned and dump  will
              assume that the filesystem does not need to be dumped.

       The sixth field (fs_passno).
              This field is used by the fsck(8) program to determine the order
              in which filesystem checks are done at reboot  time.   The  root
              filesystem  should be specified with a fs_passno of 1, and other
              filesystems should have a fs_passno of 2.  Filesystems within  a
              drive will be checked sequentially, but filesystems on different
              drives will be checked at the same time to  utilize  parallelism
              available in the hardware.  If the sixth field is not present or
              zero, a value of zero is returned and fsck will assume that  the
              filesystem does not need to be checked.

       The ancestor of this fstab file format appeared in 4.0BSD.

       This  man  page is part of the util-linux package and is available from

util-linux                        August 2010                         FSTAB(5)
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