.\" Copyright (c) 1980, 1989, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)fstab.5 8.1.1 (2.11BSD) 1996/1/15 .\" .TH FSTAB 5 "January 15, 1996" .UC 7 .SH NAME \fBfstab\fP \- static information about the filesystems .SH SYNOPSIS .B #include .SH DESCRIPTION The file .B fstab contains descriptive information about the various file systems. .B 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. The order of records in .B fstab is important because fsck(8), mount(8), and umount(8) sequentially iterate through .B fstab doing their thing. .PP The first field, .IR fs_spec , describes the block special device or remote filesystem to be mounted. For filesystems of type .IR ufs , 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. .PP The second field, .IR fs_file , describes the mount point for the filesystem. For swap partitions, this field should be specified as ``none''. .PP The third field, .IR fs_vfstype , describes the type of the filesystem. The system currently supports only two types of filesystems: .TP 15 .I ufs a local UNIX filesystem .TP 15 .I swap a disk partition to be used for swapping .PP The fourth field, .IR 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 (see .I fs_type below) plus any additional options appropriate to the filesystem type. .PP If the option ``quotas'' is specified, the filesystem is automatically processed by the quotacheck(8) command, and user disk quotas are enabled with quotaon(8). Filesystem quotas are maintained in the file named .I quotas located at the root of the associated filesystem. This restriction on the location of the quotas file is needlessly imposed by the kernel but may be lifted in the future. Thus, if the user quota file for .I /tmp is stored in .IR /var/quotas/tmp.user , this location can be specified as: .sp .in +.75i quotas=/var/quotas/tmp.user .br .in -0.75i .PP The type of the mount is extracted from the .I fs_mntops field and stored separately in the .I fs_type field (it is not deleted from the .I fs_mntops field). If .I fs_type is ``rw'' or ``ro'' then the filesystem whose name is given in the .I fs_file field is normally mounted read-write or read-only on the specified special file. If .I fs_type is ``sw'' then the special 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 .I fs_spec and .I fs_type are unused. If .I fs_type is specified as ``xx'' the entry is ignored. This is useful to show disk partitions which are currently unused. .PP The fifth field, .IR 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(8) will assume that the filesystem does not need to be dumped. .PP The sixth field, .IR fs_passno , is used by the fsck(8) program to determine the order in which filesystem checks are done at reboot time. The root filesystem should be specified with a .I fs_passno of 1, and other filesystems should have a .I 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(8) will assume that the filesystem does not need to be checked. .br .nf .cs R 24 #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 */ }; .fi .cs R .PP The proper way to read records from .I fstab is to use the routines getfsent(3), getfsspec(3), getfstype(3), and getfsfile(3). .SH FILES .TP 15 .I /etc/fstab The file .B fstab resides in .IR /etc . .SH SEE ALSO getfsent(3) .SH HISTORY The .B fstab file format appeared in 4.0BSD.