NAME

       fstab - static information about the filesystems

SYNOPSIS

       /etc/fstab

DESCRIPTION

       The  file  fstab  contains  descriptive  information  about the filesystems the system can
       mount.  fstab is only read by programs, and not written; it is  the  duty  of  the  system
       administrator to properly create and maintain this file.  The order of records in fstab is
       important because fsck(8), mount(8), and  umount(8)  sequentially  iterate  through  fstab
       doing their thing.

       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 following is a typical example of an fstab entry:

              LABEL=t-home2   /home      ext4    defaults,auto_da_alloc      0  2

       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, this field is <host>:<dir>,  e.g.,  `knuth.aeb.nl:/'.
              For  filesystems with no storage, any string can be used, and will show up in df(1)
              output, for example.  Typical usage is `proc' for procfs; `mem', `none', or `tmpfs'
              for  tmpfs.   Other  special  filesystems,  like  udev and sysfs, are typically not
              listed in fstab.

              LABEL=<label> or UUID=<uuid> may be given instead of a device name.   This  is  the
              recommended  method,  as device names are often a coincidence of hardware detection
              order, and can change  when  other  disks  are  added  or  removed.   For  example,
              `LABEL=Boot'  or  `UUID=3e6be9de-8139-11d1-9106-a43f08d823a6'.   (Use a filesystem-
              specific tool like e2label(8),  xfs_admin(8),  or  fatlabel(8)  to  set  LABELs  on
              filesystems).

              It's  also  possible  to use PARTUUID= and PARTLABEL=. These partitions identifiers
              are supported for example for GUID Partition Table (GPT).

              See mount(8), blkid(8) or lsblk(8) for more details about device identifiers.

              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 many filesystem
              types: ext4, xfs, btrfs, f2fs, vfat, ntfs, hfsplus, tmpfs,  sysfs,  proc,  iso9660,
              udf, squashfs, nfs, cifs, and many more.  For more details, see mount(8).

              An  entry  swap denotes a file or partition to be used for swapping, cf. swapon(8).
              An entry none is useful for bind or move mounts.

              More than one type may be specified in a comma-separated list.

              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
              'sshfs#example.com' is deprecated).

       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 (ro or rw), plus any additional options appropriate to the filesystem
              type   (including  performance-tuning  options).   For  details,  see  mount(8)  or
              swapon(8).

              Basic filesystem-independent options are:

              defaults
                     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

              comment
                     or x-<name> for use by fstab-maintaining programs

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

       The fifth field (fs_freq).
              This field is used by dump(8) to determine which filesystems  need  to  be  dumped.
              Defaults to zero (don't dump) if not present.

       The sixth field (fs_passno).
              This field is used by fsck(8) to determine the order in which filesystem checks are
              done at boot time.  The root filesystem should be specified with a fs_passno of  1.
              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.  Defaults to zero
              (don't fsck) if not present.

NOTES

       The proper way to read records from fstab is to use the routines getmntent(3) or libmount.

       The keyword ignore as a filesystem type (3rd field) is no longer  supported  by  the  pure
       libmount based mount utility (since util-linux v2.22).

FILES

       /etc/fstab, <fstab.h>

SEE ALSO

       findmnt(8), mount(8), swapon(8), fs(5), getmntent(3)

HISTORY

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

AVAILABILITY

       This   man   page   is   part   of   the   util-linux   package   and  is  available  from
       ftp://ftp.kernel.org/pub/linux/utils/util-linux/.