FSTAB(5)                                            Linux Programmer's Manual                                           FSTAB(5)



NAME
       fstab - static information about the filesystems

SYNOPSIS
       #include <fstab.h>

DESCRIPTION
       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.
       The order of records in fstab is important because fsck(8), mount(8), and umount(8) sequentially  iterate  through  fstab
       doing their thing.

       The first field, (fs_spec), 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.,  `knuth.aeb.nl:/'.   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.

       The second field, (fs_file), 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), 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 /proc/filesystems.   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 mounts.

       The fourth field, (fs_mntops), 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 options for non-nfs file systems, see mount(8).
       For documentation on all nfs-specific options have a look at nfs(5).  Common for all types of file system are the options
       ``noauto''  (do  not mount when "mount -a" is given, e.g., at boot time), ``user'' (allow a user to mount), and ``owner''
       (allow device owner to mount), and ``comment'' (e.g., for use by fstab-maintaining programs).  The ``owner''  and  ``com-
       ment'' options are Linux-specific.  For more details, see mount(8).

       The  fifth  field, (fs_freq), 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), 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).

FILES
       /etc/fstab

SEE ALSO
       getmntent(3), mount(8), swapon(8), fs(5), nfs(5)

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

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



Linux 2.2                                                 15 June 1999                                                  FSTAB(5)