#Bash 的 fsck 命令

FSCK(8)                      System Administration                     FSCK(8)

NAME
       fsck - check and repair a Linux filesystem

SYNOPSIS
       fsck [-lsAVRTMNP] [-r [fd]] [-C [fd]] [-t fstype] [filesystem...] [--]
       [fs-specific-options]

DESCRIPTION
       fsck is used to check and optionally repair one or more Linux
       filesystems. filesystem can be a device name (e.g., /dev/hdc1,
       /dev/sdb2), a mount point (e.g., /, /usr, /home), or a filesystem label
       or UUID specifier (e.g., UUID=8868abf6-88c5-4a83-98b8-bfc24057f7bd or
       LABEL=root). Normally, the 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.

       If no filesystems are specified on the command line, and the -A option
       is not specified, fsck will default to checking filesystems in
       /etc/fstab serially. This is equivalent to the -As options.

       The exit status returned by fsck is the sum of the following
       conditions:

       0
           No errors

       1
           Filesystem errors corrected

       2
           System should be rebooted

       4
           Filesystem errors left uncorrected

       8
           Operational error

       16
           Usage or syntax error

       32
           Checking canceled by user request

       128
           Shared-library error

       The exit status returned when multiple filesystems are checked is the
       bit-wise OR of the exit statuses for each filesystem that is checked.

       In actuality, fsck is simply a front-end for the various filesystem
       checkers (fsck.fstype) available under Linux. The filesystem-specific
       checker is searched for in the PATH environment variable. If the PATH
       is undefined then fallback to /sbin.

       Please see the filesystem-specific checker manual pages for further
       details.

OPTIONS
       -l
           Create an exclusive flock(2) lock file (/run/fsck/<diskname>.lock)
           for whole-disk device. This option can be used with one device only
           (this means that -A and -l are mutually exclusive). This option is
           recommended when more fsck instances are executed in the same time.
           The option is ignored when used for multiple devices or for
           non-rotating disks. fsck does not lock underlying devices when
           executed to check stacked devices (e.g. MD or DM) - this feature is
           not implemented yet.

       -r [fd]
           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

           GUI front-ends may specify a file descriptor fd, in which case the
           progress bar information will be sent to that file descriptor in a
           machine parsable format. For example:

           /dev/sda1 0 92828 4.002804 2.677592 0.86186

       -s
           Serialize fsck operations. This is a good idea if you are checking
           multiple filesystems and the checkers are in an interactive mode.
           (Note: e2fsck(8) runs in an interactive mode by default. To make
           e2fsck(8) run in a non-interactive mode, you must either specify
           the -p or -a option, if you wish for errors to be corrected
           automatically, or the -n option if you do not.)

       -t fslist
           Specifies the type(s) of filesystem to be checked. When the -A flag
           is specified, only filesystems that match fslist are checked. The
           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 'no' or '!', which
           requests that only those filesystems not listed in fslist will be
           checked. If none of the filesystems in fslist is prefixed by a
           negation operator, then only those listed filesystems will be
           checked.

           Options specifiers may be included in the comma-separated fslist.
           They must have the format opts=fs-option. If an options specifier
           is present, then only filesystems which contain fs-option in their
           mount options field of /etc/fstab will be checked. If the options
           specifier is prefixed by a negation operator, then only those
           filesystems that do not have fs-option in their mount options field
           of /etc/fstab will be checked.

           For example, if opts=ro appears in fslist, then only filesystems
           listed in /etc/fstab with the ro option will be checked.

           For compatibility with Mandrake distributions whose boot scripts
           depend upon an unauthorized UI change to the fsck program, if a
           filesystem type of loop is found in fslist, it is treated as if
           opts=loop were specified as an argument to the -t option.

           Normally, the filesystem type is deduced by searching for filesys
           in the /etc/fstab file and using the corresponding entry. If the
           type cannot be deduced, and there is only a single filesystem given
           as an argument to the -t option, fsck will use the specified
           filesystem type. If this type is not available, then the default
           filesystem type (currently ext2) is used.

       -A
           Walk through the /etc/fstab file and try to check all filesystems
           in one run. This option is typically used from the /etc/rc system
           initialization file, instead of multiple commands for checking a
           single filesystem.

           The root filesystem will be checked first unless the -P option is
           specified (see below). After that, filesystems will be checked in
           the order specified by the fs_passno (the sixth) field in the
           /etc/fstab file. Filesystems with a fs_passno value of 0 are
           skipped and are not checked at all. Filesystems with a fs_passno
           value of greater than zero will be checked in order, with
           filesystems with the lowest fs_passno number being checked first.
           If there are multiple filesystems with the same pass number, fsck
           will attempt to check them in parallel, although it will avoid
           running multiple filesystem checks on the same physical disk.

           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
           determine dependencies between devices.

           Hence, a very common configuration in /etc/fstab files is to set
           the root filesystem to have a fs_passno value of 1 and to set all
           other filesystems to have a fs_passno value of 2. This will allow
           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 - for example, if the
           machine in question is short on memory so that excessive paging is
           a concern.

           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 /etc/fstab mount option nofail may be used to
           have fsck skip non-existing devices. fsck also skips non-existing
           devices that have the special filesystem type auto.

       -C [fd]
           Display completion/progress bars for those filesystem checkers
           (currently only for ext[234]) which support them. fsck 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 fd, in which case the progress bar information will be
           sent to that file descriptor.

       -M
           Do not check mounted filesystems and return an exit status of 0 for
           mounted filesystems.

       -N
           Don’t execute, just show what would be done.

       -P
           When the -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
           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).

       -R
           When checking all filesystems with the -A flag, skip the root
           filesystem. (This is useful in case the root filesystem has already
           been mounted read-write.)

       -T
           Don’t show the title on startup.

       -V
           Produce verbose output, including all filesystem-specific commands
           that are executed.

       -?, --help
           Display help text and exit.

       --version
           Display version information and exit.

FILESYSTEM SPECIFIC OPTIONS
       Options which are not understood by fsck are passed to the
       filesystem-specific checker!

       These options must not take arguments, as there is no way for fsck to
       be able to properly guess which options take arguments and which don’t.

       Options and arguments which follow the -- are treated as
       filesystem-specific options to be passed to the filesystem-specific
       checker.

       Please note that fsck 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 fsck some horribly complicated options and
       arguments, and it doesn’t do what you expect, don’t bother reporting it
       as a bug. You’re almost certainly doing something that you shouldn’t be
       doing with fsck. Options to different filesystem-specific fsck’s are
       not standardized.

ENVIRONMENT
       The fsck program’s behavior is affected by the following environment
       variables:

       FSCK_FORCE_ALL_PARALLEL
           If this environment variable is set, 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.

       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 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 fsck may attempt to
           automatically determine how many filesystem checks can be run based
           on gathering accounting data from the operating system.

       PATH
           The PATH environment variable is used to find filesystem checkers.

       FSTAB_FILE
           This environment variable allows the system administrator to
           override the standard location of the /etc/fstab file. It is also
           useful for developers who are testing fsck.

       LIBBLKID_DEBUG=all
           enables libblkid debug output.

       LIBMOUNT_DEBUG=all
           enables libmount debug output.

FILES
       /etc/fstab

AUTHORS
       Theodore Ts’o <[email protected]>>, Karel Zak <[email protected]>

SEE ALSO
       fstab(5), mkfs(8), fsck.ext2(8) or fsck.ext3(8) or e2fsck(8),
       fsck.cramfs(8), fsck.jfs(8), fsck.nfs(8), fsck.minix(8), fsck.msdos(8),
       fsck.vfat(8), fsck.xfs(8), reiserfsck(8)

REPORTING BUGS
       For bug reports, use the issue tracker at
       https://github.com/util-linux/util-linux/issues.

AVAILABILITY
       The fsck command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.39.3                 2023-11-21                           FSCK(8)