.\"	$OpenBSD: fsck.8,v 1.34 2014/07/13 17:28:13 jmc Exp $
.\"	$NetBSD: fsck.8,v 1.14 1996/10/03 20:08:29 christos Exp $
.\"
.\" Copyright (c) 1996 Christos Zoulas.  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 Christos Zoulas.
.\" 4. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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.\"
.Dd $Mdocdate: July 13 2014 $
.Dt FSCK 8
.Os
.Sh NAME
.Nm fsck
.Nd file system consistency check and interactive repair
.Sh SYNOPSIS
.Nm fsck
.Bk -words
.Op Fl dfNnpvy
.Op Fl b Ar block#
.Op Fl l Ar maxparallel
.Op Fl T Ar fstype : Ns Ar fsoptions
.Op Fl t Ar fstype
.Op Ar special | node ...
.Ek
.Sh DESCRIPTION
The
.Nm
command invokes file-system-specific programs to check the
special devices listed in the
.Xr fstab 5
file or on the command line for consistency.
.Pp
It is normally used in the script
.Xr rc 8
during automatic reboot.
If no file systems are specified,
.Nm
reads the file
.Xr fstab 5
to determine which file systems to check and in what order.
Only partitions in fstab that are mounted
.Dq rw
or
.Dq ro
and that have non-zero pass numbers are checked.
File systems with pass number 1 (normally just the root file system) are
checked one at a time.
When pass 1 completes, all remaining file systems are checked, with one
process spawned per disk drive.
The disk drive containing each file system is inferred from the longest
prefix of the device name that ends in a digit; the remaining characters
are assumed to be the partition designator.
By default, file systems which are already mounted read/write are not
checked.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl b Ar block#
Causes
.Nm
to use the specified block as the location of the superblock.
Block 32 is usually an alternate super block.
This option is only valid for filesystems that support backup superblocks
(ffs and ext2fs).
.It Fl d
Debugging mode.
Just print the commands without executing them.
Available only if
.Nm
is compiled to support it.
.It Fl f
Force checking of file systems, even when they are marked clean (for file systems
that support this).
.It Fl l Ar maxparallel
Limit the number of parallel checks to
.Ar maxparallel .
By default, the limit is the number of
disks, running one process per disk.
If a smaller limit is given,
the disks are checked round-robin, one file system at a time.
.It Fl N
When using
.Xr fstab 5 ,
only check filesystems that have the
.Dq net
mount option set.
By default file systems with this option are ignored.
.It Fl n
Assume a
.Dq no
response to all questions asked by
.Nm
except for
.Dq CONTINUE? ,
which is assumed to be affirmative.
File systems will not be opened for writing.
This is the default for file systems to be checked that are
concurrently mounted writable.
.It Fl p
Enter preen mode:
.Nm
will check all file systems listed in
.Xr fstab 5
according to their pass number,
or any special devices listed on the command line,
and will make minor repairs without
human intervention.
Any major problems will cause
.Nm
to exit with a non-zero exit code,
so as to alert any invoking program or script
that human intervention is required.
.It Fl T Ar fstype : Ns Ar fsoptions
List of comma separated file system specific options for the specified
file system type, in the same format as
.Xr mount 8 .
.It Fl t Ar fstype
Invoke
.Nm
only for the comma separated list of file system types.
If the list starts with
.Dq no ,
invoke
.Nm
only in the file system types that are
.Em not
specified in
the list.
.It Fl v
Print the commands before executing them.
.It Fl y
Cause
.Nm
to assume
.Dq yes
as the answer to all operator questions.
.El
.Pp
If neither of the
.Fl y
or
.Fl n
options are specified, the user may force
.Nm
to assume an answer of
.Dq yes
to all the remaining questions by replying to a question with a value of
.Dq F .
.Sh FILES
.Bl -tag -width /etc/fstab -compact
.It Pa /etc/fstab
file system table
.El
.Sh SEE ALSO
.Xr fs 5 ,
.Xr fstab 5 ,
.Xr fsck_ext2fs 8 ,
.Xr fsck_ffs 8 ,
.Xr fsck_msdos 8 ,
.Xr fsdb 8 ,
.Xr growfs 8 ,
.Xr mount 8 ,
.Xr newfs 8 ,
.Xr rc 8 ,
.Xr scan_ffs 8