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 (target) for the filesystem.  For swap partitions, this field
              should be specified as `none'. If the name of the mount point contains spaces or tabs these can be
              escaped as `\040' and '\011' respectively.

       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

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

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
       https://www.kernel.org/pub/linux/utils/util-linux/.

util-linux                                        February 2015                                         FSTAB(5)