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 fstab(4)							    fstab(4)




 NAME
      fstab - static information about the file systems

 SYNOPSIS
      #include <&lt&lt&lt;fstab.h>&gt&gt&gt;

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

      /etc/fstab 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 /etc/fstab is important only for entries
      without a pass number field.  Entries without a pass number are
      sequentially checked by fsck (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
      additionally contain all of the following fields, in the following
      order:

		directory

		type

		options

		backup frequency

		pass number (on parallel fsck)

		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 getmntent() (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 fsck, mount, swapon, crashconf, and other
			  commands to identify the location of the storage
			  device on which the file system resides.




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 fstab(4)							    fstab(4)




      directory		  Name of the root of the mounted file system that
			  corresponds to the device special file.  If type
			  is swapfs, directory 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 swap, swapfs, dump, ignore, or a file
			  system type (for example, hfs, vxfs, cdfs, nfs, or
			  lofs).

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

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

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

			  Entries marked by the type ignore are ignored by
			  all commands and can be used to mark unused
			  sections.  If type is specified as either ignore,
			  dump, swap, or swapfs, the entry is ignored by the
			  mount and fsck commands (see mount(1M) and
			  fsck(1M)).  fsck also ignores entries with type
			  specified as cdfs, nfs, or lofs.

      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 fsck 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



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 fstab(4)							    fstab(4)




			  pass number of zero is ignored by the fsck
			  command.)

			  File systems within a drive should be assigned
			  different 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, fsck
			  checks each such file system sequentially after
			  all eligible file systems with pass numbers 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
      /etc/fstab.

 NETWORKING FEATURES
    NFS
      If the field type is nfs, a remote NFS file system is implied.  For
      NFS file systems, the device special file should be the serving
      machine name followed 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 /etc/fstab entries:

	   Add an HFS file system at /home using default mount options;
	   (backup frequency 0) fsck pass 2:

		/dev/dsk/c0t6d0 /home hfs  defaults 0 2 # /home disk

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

		/dev/vg01/lv10 / swap defaults 0 0 # swap device

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

		/dev/dsk/c0t5d0 / swap end 0 0 # swap at end of device

	   Add file system swap space on the file system containing
	   directory /swap.  type is swapfs; set options to min=10,
	   lim=4500, res=100, and pri=0 (see swapon(1M)) for explanation of
	   options).  device field is ignored but must not be empty:



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		default /swap swapfs min=10,lim=4500,res=100,pri=0 0 0

	   (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:

		/dev/dsk/c0t5d0 / dump defaults 0 0

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

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

	   server:/mnt /mnt nfs rw,hard 0 0 #mount from server.

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

 FILES
      /etc/fstab
      /usr/include/fstab.h

 SEE ALSO
      fsck(1M), mount(1M), swapon(1M), crashconf(1M), getfsent(3X),
      getmntent(3X), mnttab(4).























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