Provided by: mount_2.20.1-5.1ubuntu20.9_amd64 bug


       fstab - static information about the filesystems




       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
       comments,  blank  lines  are  ignored.  The order of records in fstab is important 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 filesystem 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.,  `'.
              For procfs, use `proc'.

              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  representation  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

              An entry swap denotes a file or partition to be used for swapping,  cf.  swapon(8).
              An  entry  ignore  causes  the  line  to  be  ignored.  This is useful to show disk
              partitions which are currently unused.  An entry none is useful for  bind  or  move

              mount(8)  and  umount(8)  support  filesystem  subtypes.  The subtype is defined by
              '.subtype' suffix.  For example  'fuse.sshfs'.  It's  recommended  to  use  subtype
              notation  rather  than  add  any  prefix  to  the  first  fstab  field (for example
              '' is depreacated).

       The fourth field (fs_mntops).
              This field describes the mount options associated with the filesystem.

              It is formatted as a comma separated list of options.  It  contains  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 time)

              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 exist.

       The  mountall(8)  program  that  mounts  filesystem during boot also recognises 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 proper way to read records from fstab is to use the routines getmntent(3) or libmount.


       /etc/fstab, <fstab.h>


       mount(8), mountall(8), swapon(8), fs(5), nfs(5), xfs(5), proc(5), getmntent(3)


       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