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FSTAB(5)		      File Formats Manual		      FSTAB(5)

NAME
       fstab --	static information about the file systems

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 file	system is described on a separate line;	fields on each
       line are	separated by tabs or spaces.  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  re-
       mote file system	to be mounted.	For file systems of type ufs, the spe-
       cial  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, (fs_file), describes the mount	 point	for  the  file
       system.	 For  swap  partitions,	 this  field  should  be  specified as
       ``none''.

       The third field,	(fs_vfstype), describes	the type of the	 file  system.
       The system can support various file system types.  Only the root, /usr,
       and  /tmp  file	systems	 need  be statically compiled into the kernel;
       everything else will be automatically loaded at	mount  time.   (Excep-
       tion:  the UFS family - FFS and LFS cannot currently be demand-loaded.)
       Some people still prefer	to statically compile other  file  systems  as
       well.

       The  fourth  field, (fs_mntops),	describes the mount options associated
       with the	file system.  It is formatted as a comma separated list	of op-
       tions.  It contains at least the	type of	mount (see fs_type below) plus
       any additional options appropriate to the file system  type.   See  the
       options	flag  (-o)  in	the mount(8) page and the file system specific
       page, such as mount_nfs(8), for additional options that may  be	speci-
       fied.

       If  the	options	``userquota'' and/or ``groupquota'' are	specified, the
       file system is automatically processed by  the  quotacheck(8)  command,
       and  user and/or	group disk quotas are enabled with quotaon(8).	By de-
       fault, file system quotas are maintained	in files named quota.user  and
       quota.group  which  are located at the root of the associated file sys-
       tem.  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 loca-
       tion can	be specified as:

	     userquota=/var/quotas/tmp.user

       If the option ``noauto''	is specified, the file system will not be  au-
       tomatically  mounted  at	 system	 startup.  Note	that, for network file
       systems of third	party types (i.e., types supported by additional soft-
       ware not	included in the	base system) to	be  automatically  mounted  at
       system  startup,	the extra_netfs_types rc.conf(5) variable must be used
       to extend the rc(8) startup script's list of network file system	types.

       The type	of the mount is	extracted from the fs_mntops field and	stored
       separately  in  the fs_type field (it is	not deleted from the fs_mntops
       field).	If fs_type is ``rw'' or	``ro'' then the	file system whose name
       is given	in the fs_file field is	normally mounted read-write  or	 read-
       only on the specified special file.  If fs_type is ``sw'' then the spe-
       cial  file  is made available as	a piece	of swap	space by the swapon(8)
       command at the end of the system	reboot procedure.   The	 fields	 other
       than fs_spec and	fs_type	are unused.  If	fs_type	is specified as	``xx''
       the entry is ignored.  This is useful to	show disk partitions which are
       currently unused.

       The  fifth  field,  (fs_freq),  is  used	 for these file	systems	by the
       dump(8) command to determine which file systems need to be dumped.   If
       the  fifth  field  is not present, a value of zero is returned and dump
       will assume that	the file system	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 file	system checks are done at reboot time.
       The root	file system should be specified	with a	fs_passno  of  1,  and
       other file systems should have a	fs_passno of 2.	 File systems within a
       drive  will be checked sequentially, but	file systems on	different dri-
       ves will	be checked at the same time to utilize	parallelism  available
       in the hardware.	 If the	sixth field is not present or is zero, a value
       of  zero	 is returned and fsck(8) will assume that the file system does
       not need	to be checked.

       #define FSTAB_RW	       "rw"    /* read/write device */
       #define FSTAB_RQ	       "rq"    /* read/write with quotas */
       #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;       /* file system path prefix */
	       char    *fs_vfstype;    /* File system type, ufs, nfs */
	       char    *fs_mntops;     /* Mount	options	ala -o */
	       char    *fs_type;       /* FSTAB_* from fs_mntops */
	       int     fs_freq;	       /* dump frequency, in days */
	       int     fs_passno;      /* pass number on parallel fsck */
       };

       The proper way to read records  from  fstab  is	to  use	 the  routines
       getfsent(3), getfsspec(3), getfstype(3),	and getfsfile(3).

FILES
       /etc/fstab  The file fstab resides in /etc.

SEE ALSO
       getfsent(3),	getvfsbyname(3),     dump(8),	 fsck(8),    mount(8),
       quotacheck(8), quotaon(8), swapon(8), umount(8)

HISTORY
       The fstab file format appeared in 4.0BSD.

GNU				 June 5, 1993			      FSTAB(5)

NAME | SYNOPSIS | DESCRIPTION | FILES | SEE ALSO | HISTORY

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