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FSTAB(5)			 File Formats			      FSTAB(5)

       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 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.

       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 de-
	      vice 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
	      filesystem  that	is  to	be  mounted  by	its UUID or LABEL (cf.
	      e2label(8)   or	xfs_admin(8)),	 writing   LABEL=<label>    or
	      UUID=<uuid>,  e.g.,  `LABEL=Boot'	 or  `UUID=3e6be9de-8139-11d1-

	      It's also	possible to use	PARTUUID= and PARTLABEL=. These	parti-
	      tions  identifiers  are supported	for GUID Partition Table (GPT)
	      and MAC partition	table only.

	      See blkid(8) or lsblk(8) for more	details	about devices  identi-

	      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,  co-
	      herent,  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-
	      ping, cf.	swapon(8).  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

       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  con-
	      tains at least the type of mount plus any	additional options ap-
	      propriate	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

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

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

       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	getmn-
       tent(3) or libmount.

       The keyword ignore as filesystem	type (3rd field) is not	more supported
       by the pure libmount based mount	utility	(since util-linux v2.22).

       /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

util-linux			  August 2010			      FSTAB(5)


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