FSCK(8)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System Administration\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 FSCK(8)<\/p>\n
NAME<\/p>\n
fsck – check and repair a Linux filesystem<\/p>\n
SYNOPSIS<\/p>\n
fsck [-lrsAVRTMNP] [-C [fd]] [-t fstype] [filesystem…] [–] [fs-
\nspecific-options]<\/p>\n
DESCRIPTION<\/p>\n
fsck is used to check and optionally repair one or more Linux
\nfilesystems.\u00a0 filesys can be a device name (e.g.\u00a0 \/dev\/hdc1,
\n\/dev\/sdb2), a mount point (e.g.\u00a0 \/, \/usr, \/home), or an ext2 label or
\nUUID specifier (e.g.\u00a0 UUID=8868abf6-88c5-4a83-98b8-bfc24057f7bd or
\nLABEL=root).\u00a0 Normally, the fsck program will try to handle
\nfilesystems on different physical disk drives in parallel to reduce
\nthe total amount of time needed to check all of them.<\/p>\n
If no filesystems are specified on the command line, and the -A
\noption is not specified, fsck will default to checking filesystems in
\n\/etc\/fstab serially.\u00a0 This is equivalent to the -As options.<\/p>\n
The exit code returned by fsck is the sum of the following
\nconditions:<\/p>\n
0\u00a0\u00a0\u00a0\u00a0\u00a0 No errors
\n1\u00a0\u00a0\u00a0\u00a0\u00a0 Filesystem errors corrected
\n2\u00a0\u00a0\u00a0\u00a0\u00a0 System should be rebooted
\n4\u00a0\u00a0\u00a0\u00a0\u00a0 Filesystem errors left uncorrected
\n8\u00a0\u00a0\u00a0\u00a0\u00a0 Operational error
\n16\u00a0\u00a0\u00a0\u00a0 Usage or syntax error
\n32\u00a0\u00a0\u00a0\u00a0 Checking canceled by user request
\n128\u00a0\u00a0\u00a0 Shared-library error<\/p>\n
The exit code returned when multiple filesystems are checked is the
\nbit-wise OR of the exit codes for each filesystem that is checked.<\/p>\n
In actuality, fsck is simply a front-end for the various filesystem
\ncheckers (fsck.fstype) available under Linux.\u00a0 The filesystem-
\nspecific checker is searched for in \/sbin first, then in \/etc\/fs and
\n\/etc, and finally in the directories listed in the PATH environment
\nvariable.\u00a0 Please see the filesystem-specific checker manual pages
\nfor further details.<\/p>\n
OPTIONS<\/p>\n
-l\u00a0\u00a0\u00a0\u00a0 Create an exclusive flock(2) lock file
\n(\/run\/fsck\/<diskname>.lock) for whole-disk device.\u00a0 This
\noption can be used with one device only (this means that -A
\nand -l are mutually exclusive).\u00a0 This option is recommended
\nwhen more fsck(8) instances are executed in the same time.
\nThe option is ignored when used for multiple devices or for
\nnon-rotating disks.\u00a0 fsck does not lock underlying devices
\nwhen executed to check stacked devices (e.g. MD or DM) \u2013 this
\nfeature is not implemented yet.<\/p>\n
-r\u00a0\u00a0\u00a0\u00a0 Report certain statistics for each fsck when it completes.
\nThese statistics include the exit status, the maximum run set
\nsize (in kilobytes), the elapsed all-clock time and the user
\nand system CPU time used by the fsck run.\u00a0 For example:<\/p>\n
\/dev\/sda1: status 0, rss 92828, real 4.002804, user 2.677592,
\nsys 0.86186<\/p>\n
-s\u00a0\u00a0\u00a0\u00a0 Serialize fsck operations.\u00a0 This is a good idea if you are
\nchecking multiple filesystems and the checkers are in an
\ninteractive mode.\u00a0 (Note: e2fsck(8) runs in an interactive
\nmode by default.\u00a0 To make e2fsck(8) run in a non-interactive
\nmode, you must either specify the -p or -a option, if you wish
\nfor errors to be corrected automatically, or the -n option if
\nyou do not.)<\/p>\n
-t fslist
\nSpecifies the type(s) of filesystem to be checked.\u00a0 When the
\n-A flag is specified, only filesystems that match fslist are
\nchecked.\u00a0 The fslist parameter is a comma-separated list of
\nfilesystems and options specifiers.\u00a0 All of the filesystems in
\nthis comma-separated list may be prefixed by a negation
\noperator ‘no’ or ‘!’, which requests that only those
\nfilesystems not listed in fslist will be checked.\u00a0 If none of
\nthe filesystems in fslist is prefixed by a negation operator,
\nthen only those listed filesystems will be checked.<\/p>\n
Options specifiers may be included in the comma-separated
\nfslist.\u00a0 They must have the format opts=fs-option.\u00a0 If an
\noptions specifier is present, then only filesystems which
\ncontain fs-option in their mount options field of \/etc\/fstab
\nwill be checked.\u00a0 If the options specifier is prefixed by a
\nnegation operator, then only those filesystems that do not
\nhave fs-option in their mount options field of \/etc\/fstab will
\nbe checked.<\/p>\n
For example, if opts=ro appears in fslist, then only
\nfilesystems listed in \/etc\/fstab with the ro option will be
\nchecked.<\/p>\n
For compatibility with Mandrake distributions whose boot
\nscripts depend upon an unauthorized UI change to the fsck
\nprogram, if a filesystem type of loop is found in fslist, it
\nis treated as if opts=loop were specified as an argument to
\nthe -t option.<\/p>\n
Normally, the filesystem type is deduced by searching for
\nfilesys in the \/etc\/fstab file and using the corresponding
\nentry.\u00a0 If the type can not be deduced, and there is only a
\nsingle filesystem given as an argument to the -t option, fsck
\nwill use the specified filesystem type.\u00a0 If this type is not
\navailable, then the default filesystem type (currently ext2)
\nis used.<\/p>\n
-A\u00a0\u00a0\u00a0\u00a0 Walk through the \/etc\/fstab file and try to check all
\nfilesystems in one run.\u00a0 This option is typically used from
\nthe \/etc\/rc system initialization file, instead of multiple
\ncommands for checking a single filesystem.<\/p>\n
The root filesystem will be checked first unless the -P option
\nis specified (see below).\u00a0 After that, filesystems will be
\nchecked in the order specified by the fs_passno (the sixth)
\nfield in the \/etc\/fstab file.\u00a0 Filesystems with a fs_passno
\nvalue of 0 are skipped and are not checked at all.
\nFilesystems with a fs_passno value of greater than zero will
\nbe checked in order, with filesystems with the lowest
\nfs_passno number being checked first.\u00a0 If there are multiple
\nfilesystems with the same pass number, fsck will attempt to
\ncheck them in parallel, although it will avoid running
\nmultiple filesystem checks on the same physical disk.<\/p>\n
fsck does not check stacked devices (RAIDs, dm-crypt, …) in
\nparallel with any other device.\u00a0 See below for
\nFSCK_FORCE_ALL_PARALLEL setting.\u00a0 The \/sys filesystem is used
\nto detemine dependencies between devices.<\/p>\n
Hence, a very common configuration in \/etc\/fstab files is to
\nset the root filesystem to have a fs_passno value of 1 and to
\nset all other filesystems to have a fs_passno value of 2.
\nThis will allow fsck to automatically run filesystem checkers
\nin parallel if it is advantageous to do so.\u00a0 System
\nadministrators might choose not to use this configuration if
\nthey need to avoid multiple filesystem checks running in
\nparallel for some reason \u2013 for example, if the machine in
\nquestion is short on memory so that excessive paging is a
\nconcern.<\/p>\n
fsck normally does not check whether the device actually
\nexists before calling a filesystem specific checker.
\nTherefore non-existing devices may cause the system to enter
\nfilesystem repair mode during boot if the filesystem specific
\nchecker returns a fatal error.\u00a0 The \/etc\/fstab mount option
\nnofail may be used to have fsck skip non-existing devices.
\nfsck also skips non-existing devices that have the special
\nfilesystem type auto.<\/p>\n
-C [fd]
\nDisplay completion\/progress bars for those filesystem checkers
\n(currently only for ext[234]) which support them.\u00a0 fsck will
\nmanage the filesystem checkers so that only one of them will
\ndisplay a progress bar at a time.\u00a0 GUI front-ends may specify
\na file descriptor fd, in which case the progress bar
\ninformation will be sent to that file descriptor.<\/p>\n
-M\u00a0\u00a0\u00a0\u00a0 Do not check mounted filesystems and return an exit code of 0
\nfor mounted filesystems.<\/p>\n
-N\u00a0\u00a0\u00a0\u00a0 Don’t execute, just show what would be done.<\/p>\n
-P\u00a0\u00a0\u00a0\u00a0 When the -A flag is set, check the root filesystem in parallel
\nwith the other filesystems.\u00a0 This is not the safest thing in
\nthe world to do, since if the root filesystem is in doubt
\nthings like the e2fsck(8) executable might be corrupted!\u00a0 This
\noption is mainly provided for those sysadmins who don’t want
\nto repartition the root filesystem to be small and compact
\n(which is really the right solution).<\/p>\n
-R\u00a0\u00a0\u00a0\u00a0 When checking all filesystems with the -A flag, skip the root
\nfilesystem.\u00a0 (This is useful in case the root filesystem has
\nalready been mounted read-write.)<\/p>\n
-T\u00a0\u00a0\u00a0\u00a0 Don’t show the title on startup.<\/p>\n
-V\u00a0\u00a0\u00a0\u00a0 Produce verbose output, including all filesystem-specific
\ncommands that are executed.<\/p>\n
fs-specific-options
\nOptions which are not understood by fsck are passed to the
\nfilesystem-specific checker.\u00a0 These options must not take
\narguments, as there is no way for fsck to be able to properly
\nguess which options take arguments and which don’t.<\/p>\n
Options and arguments which follow the — are treated as
\nfilesystem-specific options to be passed to the filesystem-
\nspecific checker.<\/p>\n
Please note that fsck is not designed to pass arbitrarily
\ncomplicated options to filesystem-specific checkers.\u00a0 If
\nyou’re doing something complicated, please just execute the
\nfilesystem-specific checker directly.\u00a0 If you pass fsck some
\nhorribly complicated options and arguments, and it doesn’t do
\nwhat you expect, don’t bother reporting it as a bug.\u00a0 You’re
\nalmost certainly doing something that you shouldn’t be doing
\nwith fsck.<\/p>\n
Options to different filesystem-specific fsck’s are not standardized.
\nIf in doubt, please consult the man pages of the filesystem-specific
\nchecker.\u00a0 Although not guaranteed, the following options are
\nsupported by most filesystem checkers:<\/p>\n
-a\u00a0\u00a0\u00a0\u00a0 Automatically repair the filesystem without any questions (use
\nthis option with caution).\u00a0 Note that e2fsck(8) supports -a
\nfor backward compatibility only.\u00a0 This option is mapped to
\ne2fsck’s -p option which is safe to use, unlike the -a option
\nthat some filesystem checkers support.<\/p>\n
-n\u00a0\u00a0\u00a0\u00a0 For some filesystem-specific checkers, the -n option will
\ncause the fs-specific fsck to avoid attempting to repair any
\nproblems, but simply report such problems to stdout.\u00a0 This is
\nhowever not true for all filesystem-specific checkers.\u00a0 In
\nparticular, fsck.reiserfs(8) will not report any corruption if
\ngiven this option.\u00a0 fsck.minix(8) does not support the -n
\noption at all.<\/p>\n
-r\u00a0\u00a0\u00a0\u00a0 Interactively repair the filesystem (ask for confirmations).
\nNote: It is generally a bad idea to use this option if
\nmultiple fsck’s are being run in parallel.\u00a0 Also note that
\nthis is e2fsck’s default behavior; it supports this option for
\nbackward compatibility reasons only.<\/p>\n
-y\u00a0\u00a0\u00a0\u00a0 For some filesystem-specific checkers, the -y option will
\ncause the fs-specific fsck to always attempt to fix any
\ndetected filesystem corruption automatically.\u00a0 Sometimes an
\nexpert may be able to do better driving the fsck manually.
\nNote that not all filesystem-specific checkers implement this
\noption.\u00a0 In particular fsck.minix(8) and fsck.cramfs(8) do not
\nsupport the -y option as of this writing.<\/p>\n
FILES<\/p>\n
\/etc\/fstab.<\/p>\n
ENVIRONMENT VARIABLES<\/p>\n
The fsck program’s behavior is affected by the following environment
\nvariables:<\/p>\n
FSCK_FORCE_ALL_PARALLEL
\nIf this environment variable is set, fsck will attempt to
\ncheck all of the specified filesystems in parallel, regardless
\nof whether the filesystems appear to be on the same device.
\n(This is useful for RAID systems or high-end storage systems
\nsuch as those sold by companies such as IBM or EMC.)\u00a0 Note
\nthat the fs_passno value is still used.<\/p>\n
FSCK_MAX_INST
\nThis environment variable will limit the maximum number of
\nfilesystem checkers that can be running at one time.\u00a0 This
\nallows configurations which have a large number of disks to
\navoid fsck starting too many filesystem checkers at once,
\nwhich might overload CPU and memory resources available on the
\nsystem.\u00a0 If this value is zero, then an unlimited number of
\nprocesses can be spawned.\u00a0 This is currently the default, but
\nfuture versions of fsck may attempt to automatically determine
\nhow many filesystem checks can be run based on gathering
\naccounting data from the operating system.<\/p>\n
PATH\u00a0\u00a0 The PATH environment variable is used to find filesystem
\ncheckers.\u00a0 A set of system directories are searched first:
\n\/sbin, \/sbin\/fs.d, \/sbin\/fs, \/etc\/fs, and \/etc.\u00a0 Then the set
\nof directories found in the PATH environment are searched.<\/p>\n
FSTAB_FILE
\nThis environment variable allows the system administrator to
\noverride the standard location of the \/etc\/fstab file.\u00a0 It is
\nalso useful for developers who are testing fsck.<\/p>\n
LIBBLKID_DEBUG=all
\nenables libblkid debug output.<\/p>\n
LIBMOUNT_DEBUG=all
\nenables libmount debug output.<\/p>\n
SEE ALSO<\/p>\n
fstab(5), mkfs(8), fsck.ext2(8) or fsck.ext3(8) or e2fsck(8),
\ncramfsck(8), fsck.minix(8), fsck.msdos(8), fsck.jfs(8), fsck.nfs(8),
\nfsck.vfat(8), fsck.xfs(8), reiserfsck(8).<\/p>\n
AUTHOR<\/p>\n
Theodore Ts’o \u27e8tytso@mit.edu\u27e9<\/p>\n
AVAILABILITY<\/p>\n
The fsck command is part of the util-linux package and is available
\nfrom Linux Kernel Archive
\n\u27e8ftp:\/\/ftp.kernel.org\/pub\/linux\/utils\/util-linux\/\u27e9.<\/p>\n
COLOPHON<\/p>\n
This page is part of the util-linux (a random collection of Linux
\nutilities) project.\u00a0 Information about the project can be found at
\n\u27e8https:\/\/www.kernel.org\/pub\/linux\/utils\/util-linux\/\u27e9.\u00a0 If you have a
\nbug report for this manual page, send it to
\nutil-linux@vger.kernel.org.\u00a0 This page was obtained from the
\nproject’s upstream Git repository
\n(git:\/\/git.kernel.org\/pub\/scm\/utils\/util-linux\/util-linux.git) on
\n2014-12-30.\u00a0 If you discover any rendering problems in this HTML ver\u2010
\nsion of the page, or you believe there is a better or more up-to-date
\nsource for the page, or you have corrections or improvements to the
\ninformation in this COLOPHON (which is not part of the original man\u2010
\nual page), send a mail to\u00a0man-pages@man7.org<\/p>\n
util-linux\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 February 2009\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 FSCK(8)<\/p>\n","protected":false},"excerpt":{"rendered":"
FSCK(8)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System Administration\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 FSCK(8) NAME fsck – check and repair a Linux filesystem SYNOPSIS fsck [-lrsAVRTMNP] [-C [fd]] [-t fstype] [filesystem…] [–] [fs- specific-options] DESCRIPTION fsck is used to check and optionally repair one or more Linux filesystems.\u00a0 filesys can be a device name (e.g.\u00a0 \/dev\/hdc1, \/dev\/sdb2), a mount point (e.g.\u00a0 \/, \/usr, \/home), or […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"categories":[8],"tags":[],"class_list":["post-318","post","type-post","status-publish","format-standard","hentry","category-shell"],"a3_pvc":{"activated":false,"total_views":0,"today_views":0},"_links":{"self":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts\/318","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=318"}],"version-history":[{"count":0,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts\/318\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=318"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=318"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=318"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}