xref: /freebsd/sbin/fsck/fsck.8 (revision 71fe318b852b8dfb3e799cb12ef184750f7f8eac)
1.\"	$NetBSD: fsck.8,v 1.19 1999/03/10 00:08:33 erh Exp $
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4.\" Copyright (c) 1996 Christos Zoulas.  All rights reserved.
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31.Dd April 25, 2001
32.Dt FSCK 8
33.Os
34.Sh NAME
35.Nm fsck
36.Nd file system consistency check and interactive repair
37.Sh SYNOPSIS
38.Nm
39.Op Fl dvplfyn
40.Op Fl B | F
41.Op Fl l Ar maxparallel
42.Op Fl t Ar fstype
43.Op Fl T Ar fstype : Ns Ar fsoptions
44.Op Ar special | node ...
45.Sh DESCRIPTION
46The
47.Nm
48utility invokes file system-specific programs to check
49the special devices listed in the
50.Xr fstab 5
51file or in the command line for consistency.
52.Pp
53It is normally used in the script
54.Pa /etc/rc
55during automatic reboot.
56Traditionally,
57.Nm
58is invoked before the file systems are mounted
59and all checks are done to completion at that time.
60If background checking is available,
61.Nm
62is invoked twice.
63It is first invoked at the traditional time,
64before the file systems are mounted, with the
65.Fl F
66flag to do checking on all the file systems
67that cannot do background checking.
68It is then invoked a second time,
69after the system has completed going multiuser, with the
70.Fl B
71flag to do checking on all the file systems
72that can do background checking.
73Unlike the foreground checking,
74the background checking is started asynchonously
75so that other system activity can proceed
76even on the file systems that are being checked.
77.Pp
78If no file systems are specified,
79.Nm
80reads the table
81.Pa /etc/fstab
82to determine which file systems to check.
83Only partitions in
84.Pa /etc/fstab
85that are mounted
86.Dq rw ,
87.Dq rq
88or
89.Dq ro
90and that have non-zero pass number are checked.
91Filesystems with pass number 1 (normally just the root file system)
92are always checked one at a time.
93.Pp
94If not in preen mode, the remaining entries are checked in order of
95increasing pass number one at a time.
96This is needed when interaction with
97.Nm
98is required.
99.Pp
100In preen mode, after pass 1 completes, all remaining file systems are checked,
101in pass number order running one process per disk drive in parallel for each
102pass number in increasing order.
103.Pp
104In other words:  In preen mode all pass 1 partitions are checked sequentially.
105Next all pass 2 partitions are checked in parallel, one process per disk drive.
106Next all pass 3 partitions are checked in parallel, one process per disk drive.
107etc.
108.Pp
109The disk drive containing each file system is inferred from the shortest prefix
110of the device name that ends in a digit; the remaining characters are assumed
111to be the partition and slice designators.
112.Pp
113The options are as follows:
114.Bl -tag -width indent
115.It Fl d
116Debugging mode. Just print the commands without executing them. Available
117only if
118.Nm
119is compiled to support it.
120.It Fl f
121Force checking of file systems, even when they are marked clean (for file systems
122that support this).
123.It Fl n
124Causes
125.Nm
126to assume no as the answer to all operator questions, except "CONTINUE?".
127.It Fl p
128Enter preen mode.
129In preen mode, only a restricted class of innocuous
130file system inconsistencies will be corrected.
131If unexpected inconsistencies caused by hardware or
132software failures are encounted, the check program
133will exit with a failure.
134See the manual pages for the individual check programs
135for a list of the sorts of failures that they correct
136when running in preen mode.
137.It Fl F
138Run in foreground mode.
139The check program for each file system is invoked with the
140.Fl F
141flag to determine whether it wishes to run as part of
142the boot up sequence,
143or if it is able to do its job in background after the
144system is up and running.
145A non-zero exit code indicates that it wants to run in foreground
146and the check program is invoked.
147A zero exit code indicates that it is able to run later in background
148and just a deferred message is printed.
149.It Fl B
150Run in background mode.
151The check program for each file system is invoked with the
152.Fl F
153flag to determine whether it wishes to run as part of
154the boot up sequence,
155or if it is able to do its job in background after the
156system is up and running.
157A non-zero exit code indicates that it wanted to run in foreground
158which is assumed to have been done, so the file system is skipped.
159A zero exit code indicates that it is able to run in background
160so the check program is invoked with the
161.Fl B
162flag to indicate that a check on the active file system should be done.
163When running in background mode,
164only one file system at a time will be checked.
165.It Fl t Ar fstype
166Invoke
167.Nm
168only for the comma separated list of file system types. If the
169list starts with
170.Dq no
171then invoke
172.Nm
173for the file system types that are not specified in the list.
174.It Fl v
175Print the commands before executing them.
176.It Fl y
177Causes
178.Nm
179to assume yes
180as the answer to all operator questions.
181.It Fl T Ar fstype : Ns Ar fsoptions
182List of comma separated file system specific options for the specified
183file system type, in the same format as
184.Xr mount 8 .
185.El
186.Sh FILES
187.Bl -tag -width /etc/fstab -compact
188.It Pa /etc/fstab
189file system table
190.El
191.Sh SEE ALSO
192.Xr fstab 5 ,
193.Xr fsck_ffs 8 ,
194.Xr fsck_msdosfs 8 ,
195.Xr mount 8
196