Yolinux.com

fstab manpage

Search topic Section
Get manual page for the search topic
List all commands matching the search topic
List all topics in the manpage index

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 com-
       ments.  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 filesys-
       tem.  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.

       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), ''owner''	(allow	device
       owner to mount), ''pamconsole'' (allow a user at the console to mount),
       and ''comment'' (e.g., for use  by  fstab-maintaining  programs).   The
       ''owner'',  ''pamconsole''  and ''comment'' 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 deter-
       mine 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).

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.



Linux 2.2			 15 June 1999			      FSTAB(5)
YoLinux.com Home Page
YoLinux Tutorial Index
Privacy Policy | Advertise with us | Feedback Form |
Unauthorized copying or redistribution prohibited.
    Bookmark and Share