MAN page from Other e2fsprogs-1.14-0.i386.rpm

FSCK

Section: Maintenance Commands (8)
Updated: January 1999
Index

NAME

fsck - check and repair a Linux file system

SYNOPSIS

fsck[-AVRTNP][-s][-tfstype][fs-options]filesys [ ... ]

DESCRIPTION

fsckis used to check and optionally repair a Linux file system. filesysis either the device name (e.g. /dev/hda1, /dev/sdb2) or the mount point(e.g. /, /usr, /home) for the file system. If this invocation of fsck has several filesystems on different physical disk drives to check, thenfsck will try to run them in parallel. This reduces the total amount time ittakes to check all of the filesystems, since fscktakes advantage of the parallelism of multiple disk spindles.

The exit code returned byfsckis the sum of the following conditions:
0 - No errors
1 - File system errors corrected
2 - System should be rebooted
4 - File system errors left uncorrected
8 - Operational error
16 - Usage or syntax error
128 - Shared library error
The exit code returned when all file systems are checked using the-Aoption is the bit-wise OR of the exit codes for eachfile system that is checked.

In actuality,fsckis simply a front-end for the various file system checkers(fsck.fstype) available under Linux. The filesystem-specific checker is searched for in /sbin first, then in /etc/fsand /etc, and finally in the directories listed in the PATH environmentvariable. Please see the file system-specific checker manual pages forfurther details.

OPTIONS

-A: Walk through the/etc/fstabfile and try to check all file systems in one run. This option istypically used from the/etc/rcsystem initalization file, instead of multiple commands for checkinga single file system.
The root filesystem will be checked first unless the-Poption is specified (see below). After that, filesystems will be checked in the order specified by the fs_passno (the sixth) field in the /etc/fstabfile. If there are multiple filesystems with the same pass number, e2fsck will attempt to check them in parallel, although it will avoid running multiple filesystem checks on the same physical disk. Hence, a very common configuration in /etc/fstabfiles is to set the root filesystem to have a fs_passnovalue of 1and to set all filesystems to have afs_passnovalue of 2. This will allowfsckto automatically run filesystem checkers in parallel if it is advantageousto do so. System administrators might choosenot to use this configuration if they need to avoid multiple filesystemchecks running in parallel for some reason --- for example, if themachine in question is short on memory so thatexcessive paging is a concern.
-R: When checking all file systems with the-Aflag, skip the root file system (in case it's already mounted read-write).
-T: Don't show the title on startup.
-N: Don't execute, just show what would be done.
-P: When the -Aflag 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 providedfor those sysadmins who don't want to repartition the rootfilesystem to be small and compact (which is really the right solution).
-s: Serialize fsck operations. This is a good idea if you checking multiplefilesystems 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-por-aoption, if you wish for errors to be corrected automatically, orthe -noption if you do not.)
-V: Produce verbose output, including all file system-specific commandsthat are executed.
-t fstype: Specifies the type of file system to be checked. When the-A flag is specified, only filesystems that match fstypeare checked. If fstypeis prefixed with nothen only filesystems whose type does not matchfstypeare checked.
Normally, the filesystem type is deduced by searching forfilesysin the /etc/fstab file and using the corresponding entry.If the type can not be deduced, fsckwill use the type specified by the -toption if it specifies a unique filesystem type. If this type is notavailable, then the default file system type (currently ext2) is used.
fs-options: Any options which are not understood by fsck,or which follow the--option are treated as file system-specific options to be passed to thefile system-specific checker.

Currently, standardized file system-specific options are somewhat influx. Although not guaranteed, the following options are supportedby most file system checkers:

-a: Automatically repair the file system without any questions (usethis option with caution). Note that e2fsck(8)supports -afor backwards compatibility only. This option is mapped to e2fsck's-poption which is safe to use, unlike the -a option that most file system checkers support.
-r: Interactively repair the filesystem (ask for confirmations). Note: Itis generally a bad idea to use this option if multiple fsck's are beingrun in parallel. Also note that this is e2fsck'sdefault behavior; it supports this option for backwards compatibilityreasons only.

AUTHOR

Theodore Ts'o (tytsoAATTmit.edu)

The manual page was shamelessly adapted from David Engel and Fred vanKempen's generic fsckfront end program, which was in turn shamelesslyadapted from Remy Card's version for the ext2 file system.

FILES

/etc/fstab.

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