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32 .\" @(#)fstab.5 8.1 (Berkeley) 6/5/93
40 .Nd static information about the file systems
46 contains descriptive information about the various file
49 is only read by programs, and not written;
50 it is the duty of the system administrator to properly create
51 and maintain this file.
52 Each file system is described on a separate line;
53 fields on each line are separated by tabs or spaces.
54 The order of records in
61 sequentially iterate through
67 describes the special device or
68 remote file system to be mounted.
72 describes the mount point for the file system.
73 For swap partitions, this field should be specified as ``none''.
77 describes the type of the file system.
78 The system can support various file system types.
79 Only the root, /usr, and /tmp file systems need be statically
80 compiled into the kernel;
81 everything else will be automatically loaded at mount
83 (Exception: the UFS family - FFS and LFS cannot
84 currently be demand-loaded.)
85 Some people still prefer to statically
86 compile other file systems as well.
90 describes the mount options associated with the file system.
91 It is formatted as a comma separated list of options.
92 It contains at least the type of mount (see
94 below) plus any additional options appropriate to the file system type.
99 page and the file system specific page, such as
101 for additional options that may be specified.
102 All options that can be given to the file system specific mount commands
106 They just need to be formatted a bit differently.
109 option can be used without the preceding
112 Other options need both the file system specific flag and its argument,
113 separated by an equal sign.
114 For example, mounting an
116 filesystem, the options
117 .Bd -literal -offset indent
118 -o sync -o noatime -m 644 -M 755 -u foo -g bar
122 .Bd -literal -offset indent
123 sync,noatime,-m=644,-M=755,-u=foo,-g=bar
126 in the option field of
129 If the options ``userquota'' and/or ``groupquota'' are specified,
130 the file system is automatically processed by the
132 command, and user and/or group disk quotas are enabled with
135 file system quotas are maintained in files named
139 which are located at the root of the associated file system.
140 These defaults may be overridden by putting an equal sign
141 and an alternative absolute pathname following the quota option.
142 Thus, if the user quota file for
145 .Pa /var/quotas/tmp.user ,
146 this location can be specified as:
147 .Bd -literal -offset indent
148 userquota=/var/quotas/tmp.user
151 If the option ``noauto'' is specified, the file system will not be automatically
152 mounted at system startup.
153 Note that, for network file systems
155 (i.e., types supported by additional software
156 not included in the base system)
157 to be automatically mounted at system startup,
159 .Va extra_netfs_types
161 variable must be used to extend the
163 startup script's list of network file system types.
165 The type of the mount is extracted from the
167 field and stored separately in the
169 field (it is not deleted from the
174 is ``rw'' or ``ro'' then the file system whose name is given in the
176 field is normally mounted read-write or read-only on the
177 specified special file.
180 is ``sw'' then the special file is made available as a piece of swap
183 command at the end of the system reboot procedure.
184 The fields other than
191 is specified as ``xx'' the entry is ignored.
192 This is useful to show disk partitions which are currently unused.
196 is used for these file systems by the
198 command to determine which file systems need to be dumped.
199 If the fifth field is not present, a value of zero is returned and
201 will assume that the file system does not need to be dumped.
209 programs to determine the order in which file system and quota
210 checks are done at reboot time.
213 field can be any value between 0 and
216 The root file system should be specified with a
218 of 1, and other file systems should have a
223 value of 1 is always checked sequentially and be completed before
224 another file system is processed, and it will be processed before
225 all file systems with a larger
228 For any given value of
230 file systems within a drive will be checked sequentially,
231 but file systems on different drives will be checked at the
232 same time to utilize parallelism available in the hardware.
233 Once all file system checks are complete for the current
235 the same process will start over for the next
238 If the sixth field is not present or is zero,
239 a value of zero is returned and
243 will assume that the file system does not need to be checked.
247 field can be used to implement finer control when
248 the system utilities may determine that the file system resides
249 on a different physical device, when it actually does not, as with a
252 All file systems with a lower
254 value will be completed before starting on file systems with a
258 E.g. all file systems with a
260 of 2 will be completed before any file systems with a
262 of 3 or greater are started.
263 Gaps are allowed between the different
266 E.g. file systems listed in
270 values such as 0, 1, 2, 15, 100, 200, 300, and may appear in any order
274 #define FSTAB_RW "rw" /* read/write device */
275 #define FSTAB_RQ "rq" /* read/write with quotas */
276 #define FSTAB_RO "ro" /* read-only device */
277 #define FSTAB_SW "sw" /* swap device */
278 #define FSTAB_XX "xx" /* ignore totally */
281 char *fs_spec; /* block special device name */
282 char *fs_file; /* file system path prefix */
283 char *fs_vfstype; /* File system type, ufs, nfs */
284 char *fs_mntops; /* Mount options ala -o */
285 char *fs_type; /* FSTAB_* from fs_mntops */
286 int fs_freq; /* dump frequency, in days */
287 int fs_passno; /* pass number on parallel fsck */
291 The proper way to read records from
293 is to use the routines
300 .Bl -tag -width /etc/fstab -compact
321 file format appeared in