+++ /dev/null
-.\" Copyright 1993, 1994, 1995 by Theodore Ts'o. All Rights Reserved.
-.\" This file may be copied under the terms of the GNU Public License.
-.\"
-.TH FSCK 8 "February 2009" "util-linux" "System Administration"
-.SH NAME
-fsck \- check and repair a Linux filesystem
-.SH SYNOPSIS
-.B fsck
-.RB [ \-lrsAVRTMNP ]
-.RB [ \-C
-.RI [ fd ]]
-.RB [ \-t
-.IR fstype ]
-.RI [ filesystem \&...\&]
-.RB [ \-\- ]
-.RI [ fs-specific-options ]
-.SH DESCRIPTION
-.B fsck
-is used to check and optionally repair one or more Linux filesystems.
-.I filesys
-can be a device name (e.g.
-.IR /dev/hdc1 ", " /dev/sdb2 ),
-a mount point (e.g.
-.IR / ", " /usr ", " /home ),
-or an ext2 label or UUID specifier (e.g.
-UUID=8868abf6-88c5-4a83-98b8-bfc24057f7bd or LABEL=root).
-Normally, the
-.B fsck
-program will try to handle filesystems on different physical disk drives
-in parallel to reduce the total amount of time needed to check all of them.
-.PP
-If no filesystems are specified on the command line, and the
-.B \-A
-option is not specified,
-.B fsck
-will default to checking filesystems in
-.B /etc/fstab
-serially. This is equivalent to the
-.B \-As
-options.
-.PP
-The exit code returned by
-.B fsck
-is the sum of the following conditions:
-.PP
-.RS
-.PD 0
-.TP
-.B 0
-No errors
-.TP
-.B 1
-Filesystem errors corrected
-.TP
-.B 2
-System should be rebooted
-.TP
-.B 4
-Filesystem errors left uncorrected
-.TP
-.B 8
-Operational error
-.TP
-.B 16
-Usage or syntax error
-.TP
-.B 32
-Checking canceled by user request
-.TP
-.B 128
-Shared-library error
-.PD
-.RE
-.PP
-The exit code returned when multiple filesystems are checked
-is the bit-wise OR of the exit codes for each
-filesystem that is checked.
-.PP
-In actuality,
-.B fsck
-is simply a front-end for the various filesystem checkers
-(\fBfsck\fR.\fIfstype\fR) available under Linux. The
-filesystem-specific checker is searched for in
-.I /sbin
-first, then in
-.I /etc/fs
-and
-.IR /etc ,
-and finally in the directories listed in the PATH environment
-variable. Please see the filesystem-specific checker manual pages for
-further details.
-.SH OPTIONS
-.TP
-.B \-l
-Create an exclusive
-.BR flock (2)
-lock file (/run/fsck/<diskname>.lock) for whole-disk device.
-This option can be used with one device only (this means that \fB\-A\fR and
-\fB\-l\fR are mutually exclusive). This option is recommended when more
-.BR fsck (8)
-instances are executed in the same time. The option is ignored when used for
-multiple devices or for non-rotating disks. \fBfsck\fR does not lock underlying
-devices when executed to check stacked devices (e.g.\& MD or DM) \(en this feature is
-not implemented yet.
-.TP
-.B \-r
-Report certain statistics for each fsck when it completes. These statistics
-include the exit status, the maximum run set size (in kilobytes), the elapsed
-all-clock time and the user and system CPU time used by the fsck run. For
-example:
-
-/dev/sda1: status 0, rss 92828, real 4.002804, user 2.677592, sys 0.86186
-.TP
-.B \-s
-Serialize
-.B fsck
-operations. This is a good idea if you are checking multiple
-filesystems and the checkers are in an interactive mode. (Note:
-.BR e2fsck (8)
-runs in an interactive mode by default. To make
-.BR e2fsck (8)
-run in a non-interactive mode, you must either specify the
-.B \-p
-or
-.B \-a
-option, if you wish for errors to be corrected automatically, or the
-.B \-n
-option if you do not.)
-.TP
-.BI \-t " fslist"
-Specifies the type(s) of filesystem to be checked. When the
-.B \-A
-flag is specified, only filesystems that match
-.I fslist
-are checked. The
-.I fslist
-parameter is a comma-separated list of filesystems and options
-specifiers. All of the filesystems in this comma-separated list may be
-prefixed by a negation operator
-.RB ' no '
-or
-.RB ' ! ',
-which requests that only those filesystems not listed in
-.I fslist
-will be checked. If none of the filesystems in
-.I fslist
-is prefixed by a negation operator, then only those listed filesystems
-will be checked.
-.sp
-Options specifiers may be included in the comma-separated
-.IR fslist .
-They must have the format
-.BI opts= fs-option\fR.
-If an options specifier is present, then only filesystems which contain
-.I fs-option
-in their mount options field of
-.B /etc/fstab
-will be checked. If the options specifier is prefixed by a negation
-operator, then only
-those filesystems that do not have
-.I fs-option
-in their mount options field of
-.B /etc/fstab
-will be checked.
-.sp
-For example, if
-.B opts=ro
-appears in
-.IR fslist ,
-then only filesystems listed in
-.B /etc/fstab
-with the
-.B ro
-option will be checked.
-.sp
-For compatibility with Mandrake distributions whose boot scripts
-depend upon an unauthorized UI change to the
-.B fsck
-program, if a filesystem type of
-.B loop
-is found in
-.IR fslist ,
-it is treated as if
-.B opts=loop
-were specified as an argument to the
-.B \-t
-option.
-.sp
-Normally, the filesystem type is deduced by searching for
-.I filesys
-in the
-.I /etc/fstab
-file and using the corresponding entry.
-If the type can not be deduced, and there is only a single filesystem
-given as an argument to the
-.B \-t
-option,
-.B fsck
-will use the specified filesystem type. If this type is not
-available, then the default filesystem type (currently ext2) is used.
-.TP
-.B \-A
-Walk through the
-.I /etc/fstab
-file and try to check all filesystems in one run. This option is
-typically used from the
-.I /etc/rc
-system initialization file, instead of multiple commands for checking
-a single filesystem.
-.sp
-The root filesystem will be checked first unless the
-.B \-P
-option is specified (see below). After that,
-filesystems will be checked in the order specified by the
-.I fs_passno
-(the sixth) field in the
-.I /etc/fstab
-file.
-Filesystems with a
-.I fs_passno
-value of 0 are skipped and are not checked at all. Filesystems with a
-.I fs_passno
-value of greater than zero will be checked in order,
-with filesystems with the lowest
-.I fs_passno
-number being checked first.
-If there are multiple filesystems with the same pass number,
-.B fsck
-will attempt to check them in parallel, although it will avoid running
-multiple filesystem checks on the same physical disk.
-.sp
-.B fsck
-does not check stacked devices (RAIDs, dm-crypt, \&...\&) in parallel with any other
-device. See below for FSCK_FORCE_ALL_PARALLEL setting. The /sys filesystem is
-used to detemine dependencies between devices.
-.sp
-Hence, a very common configuration in
-.I /etc/fstab
-files is to set the root filesystem to have a
-.I fs_passno
-value of 1
-and to set all other filesystems to have a
-.I fs_passno
-value of 2. This will allow
-.B fsck
-to automatically run filesystem checkers in parallel if it is advantageous
-to do so. System administrators might choose
-not to use this configuration if they need to avoid multiple filesystem
-checks running in parallel for some reason \(en for example, if the
-machine in question is short on memory so that
-excessive paging is a concern.
-.sp
-.B fsck
-normally does not check whether the device actually exists before
-calling a filesystem specific checker. Therefore non-existing
-devices may cause the system to enter filesystem repair mode during
-boot if the filesystem specific checker returns a fatal error. The
-.B /etc/fstab
-mount option
-.B nofail
-may be used to have
-.B fsck
-skip non-existing devices.
-.B fsck
-also skips non-existing devices that have the special filesystem type
-.BR auto .
-.TP
-.BR \-C \ [ \fIfd\fR ]
-Display completion/progress bars for those filesystem checkers (currently
-only for ext[234]) which support them. \fBfsck\fR will manage the
-filesystem checkers so that only one of them will display
-a progress bar at a time. GUI front-ends may specify a file descriptor
-.IR fd ,
-in which case the progress bar information will be sent to that file descriptor.
-.TP
-.B \-M
-Do not check mounted filesystems and return an exit code of 0
-for mounted filesystems.
-.TP
-.B \-N
-Don't execute, just show what would be done.
-.TP
-.B \-P
-When the
-.B \-A
-flag is set, check the root filesystem in parallel with the other filesystems.
-This is not the safest thing in the world to do,
-since if the root filesystem is in doubt things like the
-.BR e2fsck (8)
-executable might be corrupted! This option is mainly provided
-for those sysadmins who don't want to repartition the root
-filesystem to be small and compact (which is really the right solution).
-.TP
-.B \-R
-When checking all filesystems with the
-.B \-A
-flag, skip the root filesystem. (This is useful in case the root
-filesystem has already been mounted read-write.)
-.TP
-.B \-T
-Don't show the title on startup.
-.TP
-.B \-V
-Produce verbose output, including all filesystem-specific commands
-that are executed.
-.TP
-.B fs-specific-options
-Options which are not understood by
-.B fsck
-are passed to the filesystem-specific checker. These options
-.B must
-not take arguments, as there is no
-way for
-.B fsck
-to be able to properly guess which options take arguments and which
-don't.
-.IP
-Options and arguments which follow the
-.B \-\-
-are treated as filesystem-specific options to be passed to the
-filesystem-specific checker.
-.IP
-Please note that \fBfsck\fR is not
-designed to pass arbitrarily complicated options to filesystem-specific
-checkers. If you're doing something complicated, please just
-execute the filesystem-specific checker directly. If you pass
-.B fsck
-some horribly complicated options and arguments, and it doesn't do
-what you expect,
-.B don't bother reporting it as a bug.
-You're almost certainly doing something that you shouldn't be doing
-with
-.BR fsck .
-.PP
-Options to different filesystem-specific fsck's are not standardized.
-If in doubt, please consult the man pages of the filesystem-specific
-checker. Although not guaranteed, the following options are supported
-by most filesystem checkers:
-.TP
-.B \-a
-Automatically repair the filesystem without any questions (use
-this option with caution). Note that
-.BR e2fsck (8)
-supports
-.B \-a
-for backward compatibility only. This option is mapped to
-.BR e2fsck 's
-.B \-p
-option which is safe to use, unlike the
-.B \-a
-option that some filesystem checkers support.
-.TP
-.B \-n
-For some filesystem-specific checkers, the
-.B \-n
-option will cause the fs-specific fsck to avoid attempting to repair any
-problems, but simply report such problems to stdout. This is however
-not true for all filesystem-specific checkers. In particular,
-.BR fsck.reiserfs (8)
-will not report any corruption if given this option.
-.BR fsck.minix (8)
-does not support the
-.B \-n
-option at all.
-.TP
-.B \-r
-Interactively repair the filesystem (ask for confirmations). Note: It
-is generally a bad idea to use this option if multiple fsck's are being
-run in parallel. Also note that this is
-.BR e2fsck 's
-default behavior; it supports this option for backward compatibility
-reasons only.
-.TP
-.B \-y
-For some filesystem-specific checkers, the
-.B \-y
-option will cause the fs-specific fsck to always attempt to fix any
-detected filesystem corruption automatically. Sometimes an expert may
-be able to do better driving the fsck manually. Note that
-.B not
-all filesystem-specific checkers implement this option. In particular
-.BR fsck.minix (8)
-and
-.BR fsck.cramfs (8)
-do not support the
-.B \-y
-option as of this writing.
-.SH FILES
-.IR /etc/fstab .
-.SH ENVIRONMENT VARIABLES
-The
-.B fsck
-program's behavior is affected by the following environment variables:
-.TP
-.B FSCK_FORCE_ALL_PARALLEL
-If this environment variable is set,
-.B fsck
-will attempt to check all of the specified filesystems in parallel, regardless of
-whether the filesystems appear to be on the same device. (This is useful for
-RAID systems or high-end storage systems such as those sold by companies such
-as IBM or EMC.) Note that the fs_passno value is still used.
-.TP
-.B FSCK_MAX_INST
-This environment variable will limit the maximum number of filesystem
-checkers that can be running at one time. This allows configurations
-which have a large number of disks to avoid
-.B fsck
-starting too many filesystem checkers at once, which might overload
-CPU and memory resources available on the system. If this value is
-zero, then an unlimited number of processes can be spawned. This is
-currently the default, but future versions of
-.B fsck
-may attempt to automatically determine how many filesystem checks can
-be run based on gathering accounting data from the operating system.
-.TP
-.B PATH
-The
-.B PATH
-environment variable is used to find filesystem checkers. A set of
-system directories are searched first:
-.BR /sbin ,
-.BR /sbin/fs.d ,
-.BR /sbin/fs ,
-.BR /etc/fs ,
-and
-.BR /etc .
-Then the set of directories found in the
-.B PATH
-environment are searched.
-.TP
-.B FSTAB_FILE
-This environment variable allows the system administrator
-to override the standard location of the
-.B /etc/fstab
-file. It is also useful for developers who are testing
-.BR fsck .
-.TP
-.B LIBBLKID_DEBUG=all
-enables libblkid debug output.
-.TP
-.B LIBMOUNT_DEBUG=all
-enables libmount debug output.
-.SH SEE ALSO
-.na
-.BR fstab (5),
-.BR mkfs (8),
-.BR fsck.ext2 (8)
-or
-.BR fsck.ext3 (8)
-or
-.BR e2fsck (8),
-.BR cramfsck (8),
-.BR fsck.minix (8),
-.BR fsck.msdos (8),
-.BR fsck.jfs (8),
-.BR fsck.nfs (8),
-.BR fsck.vfat (8),
-.BR fsck.xfs (8),
-.BR reiserfsck (8).
-.ad
-.SH AUTHOR
-.MT tytso@mit.edu
-Theodore Ts'o
-.ME
-.SH AVAILABILITY
-The fsck command is part of the util-linux package and is available from
-.UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
-Linux Kernel Archive
-.UE .
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