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[unix-history] / usr / share / man / cat5 / fstab.0

FSTAB(5)		      1990			 FSTAB(5)



N\bNA\bAM\bME\bE
     fstab - static information about the filesystems

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     #\b#i\bin\bnc\bcl\blu\bud\bde\be <\b<f\bfs\bst\bta\bab\bb.\b.h\bh>\b>

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     The file /_\be_\bt_\bc/_\bf_\bs_\bt_\ba_\bb contains descriptive information about
     the various file systems.	/_\be_\bt_\bc/_\bf_\bs_\bt_\ba_\bb is only read by pro-
     grams, 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.  The order of
     records in /_\be_\bt_\bc/_\bf_\bs_\bt_\ba_\bb is important because _\bf_\bs_\bc_\bk, _\bm_\bo_\bu_\bn_\bt, and
     _\bu_\bm_\bo_\bu_\bn_\bt sequentially iterate through /_\be_\bt_\bc/_\bf_\bs_\bt_\ba_\bb doing their
     thing.

     The first field, (_\bf_\bs__\bs_\bp_\be_\bc), describes the block special dev-
     ice or remote filesystem to be mounted.  For filesystems of
     type u\buf\bfs\bs, the special file name is the block special file
     name, and not the character special file name.  If a program
     needs the character special file name, the program must
     create it by appending a ``r'' after the last ``/'' in the
     special file name.

     The second field, (_\bf_\bs__\bf_\bi_\bl_\be), describes the mount point for
     the filesystem.  For swap partitions, this field should be
     specified as ``none''.

     The third field, (_\bf_\bs__\bv_\bf_\bs_\bt_\by_\bp_\be), describes the type of the
     filesystem.  The system currently supports four types of
     filesystems:

     u\buf\bfs\bs     a local UNIX filesystem

     m\bmf\bfs\bs     a local memory-based UNIX filesystem

     n\bnf\bfs\bs     a Sun Microsystems compatible ``Network File Sys-
	     tem''

     s\bsw\bwa\bap\bp    a disk partition to be used for swapping

     The fourth field, (_\bf_\bs__\bm_\bn_\bt_\bo_\bp_\bs), 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 (see _\bf_\bs__\bt_\by_\bp_\be below) plus any additional options
     appropriate to the filesystem type.

     If the options ``userquota'' and/or ``groupquota'' are
     specified, the filesystem is automatically processed by the
     _\bq_\bu_\bo_\bt_\ba_\bc_\bh_\be_\bc_\bk(8) command, and user and/or group disk quotas are
     enabled with _\bq_\bu_\bo_\bt_\ba_\bo_\bn(8).  By default, filesystem quotas are



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FSTAB(5)		      1990			 FSTAB(5)



     maintained in files named _\bq_\bu_\bo_\bt_\ba._\bu_\bs_\be_\br and _\bq_\bu_\bo_\bt_\ba._\bg_\br_\bo_\bu_\bp which
     are located at the root of the associated filesystem.  These
     defaults may be overridden by putting an equal sign and an
     alternative absolute pathname following the quota option.
     Thus, if the user quota file for /tmp is stored in
     /var/quotas/tmp.user, this location can be specified as:

	       userquota=/var/quotas/tmp.user

     The type of the mount is extracted from the _\bf_\bs__\bm_\bn_\bt_\bo_\bp_\bs field
     and stored separately in the _\bf_\bs__\bt_\by_\bp_\be field (it is not
     deleted from the _\bf_\bs__\bm_\bn_\bt_\bo_\bp_\bs field).  If _\bf_\bs__\bt_\by_\bp_\be is ``rw'' or
     ``ro'' then the filesystem whose name is given in the
     _\bf_\bs__\bf_\bi_\bl_\be field is normally mounted read-write or read-only on
     the specified special file.  If _\bf_\bs__\bt_\by_\bp_\be is ``sw'' then the
     special file is made available as a piece of swap space by
     the _\bs_\bw_\ba_\bp_\bo_\bn(8) command at the end of the system reboot pro-
     cedure.  The fields other than _\bf_\bs__\bs_\bp_\be_\bc and _\bf_\bs__\bt_\by_\bp_\be are
     unused.  If _\bf_\bs__\bt_\by_\bp_\be is specified as ``xx'' the entry is
     ignored.  This is useful to show disk partitions which are
     currently unused.

     The fifth field, (_\bf_\bs__\bf_\br_\be_\bq), is used for these filesystems by
     the _\bd_\bu_\bm_\bp(8) command to determine which filesystems need to
     be dumped.  If the fifth field is not present, a value of
     zero is returned and _\bd_\bu_\bm_\bp will assume that the filesystem
     does not need to be dumped.

     The sixth field, (_\bf_\bs__\bp_\ba_\bs_\bs_\bn_\bo), is used by the _\bf_\bs_\bc_\bk(8) program
     to determine the order in which filesystem checks are done
     at reboot time.  The root filesystem should be specified
     with a _\bf_\bs__\bp_\ba_\bs_\bs_\bn_\bo of 1, and other filesystems should have a
     _\bf_\bs__\bp_\ba_\bs_\bs_\bn_\bo 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 _\bf_\bs_\bc_\bk will assume that the
     filesystem does not need to be checked.

     #define   FSTAB_RW  "rw" /* read-write device */
     #define   FSTAB_RO  "ro" /* read-only device */
     #define   FSTAB_SW  "sw" /* swap device */
     #define   FSTAB_XX  "xx" /* ignore totally */

     struct fstab {
	     char  *fs_spec;	 /* block special device name */
	     char  *fs_file;	 /* filesystem path prefix */
	     char  *fs_vfstype;  /* type of filesystem */
	     char  *fs_mntops;	 /* comma separated mount options */
	     char  *fs_type;	 /* rw, ro, sw, or xx */
	     int   fs_freq;	 /* dump frequency, in days */
	     int   fs_passno;	 /* pass number on parallel dump */



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FSTAB(5)		      1990			 FSTAB(5)



     };

     The proper way to read records from /_\be_\bt_\bc/_\bf_\bs_\bt_\ba_\bb is to use the
     routines getfsent(), getfsspec(), getfstype(), and getfs-
     file().

F\bFI\bIL\bLE\bES\bS
     /etc/fstab

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     getfsent(3)












































Printed 7/27/90               June				3