Provided by: mount_2.27.1-6ubuntu2_i386 bug


       fstab - static information about the filesystems




       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

       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., `'.  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

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

       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 '' is

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

              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

              Basic filesystem-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

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

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

       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

       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


       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


       /etc/fstab, <fstab.h>


       findmnt(8), mount(8), swapon(8), fs(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