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fstab(4)		    Kernel Interfaces Manual			fstab(4)

NAME
     fstab - static information about the file systems

SYNOPSIS
DESCRIPTION
     is  an  ASCII  file  that resides in directory Programs read it, but do not
     write to or from it.  System administrators are  responsible  for	creating
     and maintaining this file properly.

     contains  a  list of mountable file-system entries.  Each file-system entry
     appears on a separate line, and consists of fields separated by one or more
     blanks or tabs.

     The order of entries in is important only for entries without a pass number
     field.  Entries without a pass number  are  sequentially  checked	by  (see
     fsck(1M)) after the entries with a pass number have been checked.

     Each file-system entry must contain a device special file and may addition-
     ally contain all of the following fields, in the following order:

		 directory

		 type

		 options

		 backup frequency

		 pass number (on parallel

		 comment

     If  any  field  after  the  name of the device special file is present, all
     fields must be present in the order indicated,  to  ensure  correct  place-
     holding.

     Entries from this file are accessed using (see getmntent(3X)).

     The  fields are separated by white space, and a as the first non-whitespace
     character in an entry or field indicates a comment.

     device special file
			 A block device special file name.  This field	is  used
			 by  and  other commands to identify the location of the
			 storage device on which the file system resides.

     directory		 Name of the root of the mounted file system that corre-
			 sponds to the device special file.  If type  is  direc-
			 tory  can  be	the  name of any directory within a file
			 system.  Only one directory  should  be  specified  per
			 file  system.	directory must already exist and must be
			 given as an absolute path name.

     type		 Can be or a file system type (for example, or

			 If type is the device special file is made available as
			 an area of swap space by the command (see  swapon(1M)).
			 The options field is valid.  The fields directory, pass
			 number, and backup frequency are ignored for entries.

			 If  type  is the file system in which directory resides
			 is made available as swap space by The options field is
			 valid.  The fields device special  file,  pass  number,
			 and backup frequency are ignored for entries.

			 If type is the device special file is made available as
			 an  area  into  which a system crash dump may occur, by
			 the command (see crashconf(1M)).  The	fields	options,
			 directory,  pass  number,  and backup frequency are ig-
			 nored for entries.

			 Entries marked by the type are ignored by all	commands
			 and  can  be  used to mark unused sections.  If type is
			 specified as either or the entry is ignored by the  and
			 commands  (see  mount(1M) and fsck(1M)).  fsck also ig-
			 nores entries with type specified as or

     options		 A comma-separated list of option keywords, as found  in
			 mount(1M)  or	swapon(1M).  The keywords used depend on
			 the parameter specified in type.

     backup frequency	 Reserved for possible use by future backup utilities.

     pass number	 Used by the command to determine  the	order  in  which
			 file  system  checks  are  done.   The root file system
			 should be specified with a pass  number  of  1,  to  be
			 checked  first,  and  other  file  systems  should have
			 larger numbers.  (A file system with a pass  number  of
			 zero is ignored by the command.)

			 File  systems within a drive should be assigned differ-
			 ent pass numbers, but file systems on different  drives
			 can  be  checked  on the same pass, to utilize possible
			 parallelism available in the hardware.  If pass  number
			 is  not  present,  checks each such file system sequen-
			 tially after all eligible file systems with  pass  num-
			 bers have been checked.

     comment		 An optional field that begins with a character and ends
			 with  a new-line character.  Space from the pass number
			 to the comment field (if present) or to the new-line is
			 reserved for future use.

     There is no limit to the number of device special file fields in

NETWORKING FEATURES
   NFS
     If the field type is a remote NFS file system is  implied.   For  NFS  file
     systems,  the  device  special file should be the serving machine name fol-
     lowed by ":" followed by the path on the serving machine of  the  directory
     being  served.  The pass number and backup frequency fields are ignored for
     NFS entries.

EXAMPLES
     Examples of typical entries:

	    Add an HFS file system at using default mount options; (backup  fre-
	    quency 0) fsck pass 2:

	    Add  a  device  to	a system managed using LVM, with default options
	    (Note, the directory field cannot be empty, even though  it  is  ig-
	    nored):

	    Add  a swap device on a system implementing whole-disk layout to use
	    the space after the end of the file system (options

	    Add file system swap space on the file system  containing  directory
	    type  is  set options to and (see swapon(1M)) for explanation of op-
	    tions).  device field is ignored but must not be empty:

	    (Note that both a file system entry and a swap  entry  are	required
	    for devices providing both services.)

	    Use  a device for dump space if the system crashes.  directory field
	    is ignored but must not be empty:

	    (Note that both a swap entry and a dump entry are required	for  de-
	    vices providing both services.)

DEPENDENCIES
   NFS
     Here is an example for mounting an NFS file system for systems that support
     NFS file systems:

AUTHOR
     fstab was developed by HP, AT&T, Sun Microsystems, Inc., and the University
     of California, Berkeley.

FILES
SEE ALSO
     fsck(1M),	 mount(1M),   swapon(1M),  crashconf(1M),  getfsent(3X),  getmn-
     tent(3X), mnttab(4).

									fstab(4)
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