mount/fstab.5

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  32 .\"     @(#)fstab.5     6.5 (Berkeley) 5/10/91
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  34 .\" Modified Sat Mar  6 20:45:03 1993, faith@cs.unc.edu, for Linux
  35 .\" Sat Oct  9 10:07:10 1993: converted to man format by faith@cs.unc.edu
  36 .\" Sat Nov 20 20:47:38 1993: hpfs documentation added
  37 .\" Sat Nov 27 20:23:32 1993: Updated authorship information
  38 .\" Wed Jul 26 00:00:00 1995: Updated some nfs stuff, joey@infodrom.north.de
  39 .\"
  40 .TH FSTAB 5 "27 November 1993" "Linux 0.99" "Linux Programmer's Manual"
  41 .SH NAME
  42 fstab \- static information about the filesystems
  43 .SH SYNOPSIS
  44 .B #include <fstab.h>
  45 .SH DESCRIPTION
  46 The file
  47 .B fstab
  48 contains descriptive information about the various file systems.
  49 .B fstab
  50 is only read by programs, and not written; it is the duty of the system
  51 administrator to properly create and maintain this file.  Each filesystem
  52 is described on a separate line; fields on each line are separated by tabs
  53 or spaces.  The order of records in
  54 .B fstab
  55 is important because
  56 .BR fsck "(8), " mount "(8), and " umount "(8)
  57 sequentially iterate through
  58 .B fstab
  59 doing their thing.
  60
  61 The first field,
  62 .RI ( fs_spec ),
  63 describes the block special device or
  64 remote filesystem to be mounted.
  65
  66 The second field,
  67 .RI ( fs_file ),
  68 describes the mount point for the filesystem.  For swap partitions, this
  69 field should be specified as ``none''.
  70
  71 The third field,
  72 .RI ( fs_vfstype ),
  73 describes the type of the filesystem.  The system currently supports three
  74 types of filesystems:
  75 .TP
  76 .I minix
  77 a local filesystem, supporting filenames of length 14 or 30 characters.
  78 .TP
  79 .I ext
  80 a local filesystem with longer filenames and larger inodes.  This
  81 filesystem has been replaced by the
  82 .I ext2
  83 file system, and should no longer be used.
  84 .TP
  85 .I ext2
  86 a local filesystem with longer filenames, larger inodes, and lots of other
  87 features.
  88 .TP
  89 .I xiafs
  90 a local filesystem with longer filenames, larger inodes, and lots of other
  91 features.
  92 .TP
  93 .I msdos
  94 a local filesystem for MS-DOS partitions.
  95 .TP
  96 .I hpfs
  97 a local filesystem for HPFS partitions.
  98 .TP
  99 .I iso9660
 100 a local filesystem used for CD-ROM drives.
 101 .TP
 102 .I nfs
 103 a filesystem for mounting partitions from remote systems.
 104 .TP
 105 .I swap
 106 a disk partition to be used for swapping.
 107 .PP
 108 If
 109 .I vfs_fstype
 110 is specified as ``ignore'' the entry is ignored.  This is useful to show
 111 disk partitions which are currently unused.
 112
 113 The fourth field,
 114 .RI ( fs_mntops ),
 115 describes the mount options associated with the filesystem.
 116
 117 It is formatted as a comma separated list of options.  It contains at least
 118 the type of mount plus any additional options appropriate to the filesystem
 119 type.  For documentation on the available options for non-nfs file systems,
 120 see
 121 .BR mount (8).
 122 For documentation on all nfs-specific options have a look at
 123 .BR nfs (5).
 124
 125 The fifth field,
 126 .RI ( fs_freq ),
 127 is used for these filesystems by the
 128 .BR dump (8)
 129 command to determine which filesystems need to be dumped.  If the fifth
 130 field is not present, a value of zero is returned and
 131 .B dump
 132 will assume that the filesystem does not need to be dumped.
 133
 134 The sixth field,
 135 .RI ( fs_passno ),
 136 is used by the
 137 .BR fsck (8)
 138 program to determine the order in which filesystem checks are done at
 139 reboot time.  The root filesystem should be specified with a
 140 .I fs_passno
 141 of 1, and other filesystems should have a
 142 .I fs_passno
 143 of 2.  Filesystems within a drive will be checked sequentially, but
 144 filesystems on different drives will be checked at the same time to utilize
 145 parallelism available in the hardware.  If the sixth field is not present
 146 or zero, a value of zero is returned and
 147 .B fsck
 148 will assume that the filesystem does not need to be checked.
 149
 150 The proper way to read records from
 151 .B fstab
 152 is to use the routines
 153 .BR getmntent (3).
 154 .SH FILES
 155 .I /etc/fstab
 156 The file
 157 .B fstab
 158 resides in
 159 .IR /etc .
 160 .SH BUGS
 161 The documentation in
 162 .BR mount (8)
 163 is often more up-to-date.
 164 .SH "SEE ALSO"
 165 .BR getmntent "(3), " mount "(8), " swapon "(8), " nfs (5)
 166 .SH HISTORY
 167 The
 168 .B fstab
 169 file format appeared in 4.0BSD.