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.\" Copyright 1993, 1994, 1995 by Theodore Ts'o. All Rights Reserved.
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.\" This file may be copied under the terms of the GNU Public License.
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.TH E2FSCK 8 "May 2010" "E2fsprogs version 1.41.12"
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e2fsck \- check a Linux ext2/ext3/ext4 file system
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is used to check the ext2/ext3/ext4 family of file systems.
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For ext3 and ext4 filesystems that use a journal, if the system has been
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shut down uncleanly without any errors, normally, after replaying the
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committed transactions in the journal, the file system should be
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marked as clean. Hence, for filesystems that use journalling,
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will normally replay the journal and exit, unless its superblock
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indicates that further checking is required.
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is the device file where the filesystem is stored (e.g.
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Note that in general it is not safe to run
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on mounted filesystems. The only exception is if the
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option is specified, and
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specified. However, even if it is safe to do so, the results printed by
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are not valid if the filesystem is mounted. If
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asks whether or not you should check a filesystem which is mounted,
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the only correct answer is ``no''. Only experts who really know what
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they are doing should consider answering this question in any other way.
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This option does the same thing as the
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option. It is provided for backwards compatibility only; it is
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suggested that people use
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option whenever possible.
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Instead of using the normal superblock, use an alternative superblock
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This option is normally used when the primary superblock has been
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corrupted. The location of the backup superblock is dependent on the
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filesystem's blocksize. For filesystems with 1k blocksizes, a backup
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superblock can be found at block 8193; for filesystems with 2k
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blocksizes, at block 16384; and for 4k blocksizes, at block 32768.
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Additional backup superblocks can be determined by using the
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option to print out where the superblocks were created. The
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which specifies blocksize of the filesystem must be specified in order
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for the superblock locations that are printed out to be accurate.
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If an alternative superblock is specified and
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the filesystem is not opened read-only, e2fsck will make sure that the
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primary superblock is updated appropriately upon completion of the
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will search for the superblock at various different
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block sizes in an attempt to find the appropriate block size.
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This search can be fooled in some cases. This option forces
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to only try locating the superblock at a particular blocksize.
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If the superblock is not found,
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will terminate with a fatal error.
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program to do a read-only scan of the device in order to find any bad
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blocks. If any bad blocks are found, they are added to the bad block
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inode to prevent them from being allocated to a file or directory. If
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this option is specified twice, then the bad block scan will be done
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using a non-destructive read-write test.
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to write completion information to the specified file descriptor
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so that the progress of the filesystem
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check can be monitored. This option is typically used by programs
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If the file descriptor number is negative, then absolute value of
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the file descriptor will be used, and the progress information will be
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suppressed initially. It can later be enabled by sending the
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process a SIGUSR1 signal.
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If the file descriptor specified is 0,
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will print a completion bar as it goes about its business. This requires
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that e2fsck is running on a video console or terminal.
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Print debugging output (useless unless you are debugging
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Optimize directories in filesystem. This option causes e2fsck to
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try to optimize all directories, either by reindexing them if the
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filesystem supports directory indexing, or by sorting and compressing
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directories for smaller directories, or for filesystems using
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traditional linear directories.
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may sometimes optimize a few directories --- for example, if
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directory indexing is enabled and a directory is not indexed and would
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benefit from being indexed, or if the index structures are corrupted
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and need to be rebuilt. The
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option forces all directories in the filesystem to be optimized. This can
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sometimes make them a little smaller and slightly faster to search, but
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in practice, you should rarely need to use this option.
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option will detect directory entries with duplicate names in a single
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directory, which e2fsck normally does not enforce for performance reasons.
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.BI \-E " extended_options"
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Set e2fsck extended options. Extended options are comma
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separated, and may take an argument using the equals ('=') sign. The
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following options are supported:
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.BI ea_ver= extended_attribute_version
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Set the version of the extended attribute blocks which
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will require while checking the filesystem. The version number may
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be 1 or 2. The default extended attribute version format is 2.
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During pass 1, print a detailed report of any discontiguous blocks for
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files in the filesystem.
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Force checking even if the file system seems clean.
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Flush the filesystem device's buffer caches before beginning. Only
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really useful for doing
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.BI \-j " external-journal"
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Set the pathname where the external-journal for this filesystem can be
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When combined with the
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option, any existing bad blocks in the bad blocks list are preserved,
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and any new bad blocks found by running
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will be added to the existing bad blocks list.
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Add the block numbers listed in the file specified by
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to the list of bad blocks. The format of this file is the same as the
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program. Note that the block numbers are based on the blocksize
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of the filesystem. Hence,
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must be given the blocksize of the filesystem in order to obtain correct
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results. As a result, it is much simpler and safer to use the
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since it will assure that the correct parameters are passed to the
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Set the bad blocks list to be the list of blocks specified by
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(This option is the same as the
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option, except the bad blocks list is cleared before the blocks listed
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in the file are added to the bad blocks list.)
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Open the filesystem read-only, and assume an answer of `no' to all
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to be used non-interactively. This option
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may not be specified at the same time as the
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Automatically repair ("preen") the file system. This option will cause
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fix any filesystem problems that can be safely fixed without human
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discovers a problem which may require the system administrator
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to take additional corrective action,
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will print a description of the problem and then exit with the value 4
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logically or'ed into the exit code. (See the \fBEXIT CODE\fR section.)
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This option is normally used by the system's boot scripts. It may not
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be specified at the same time as the
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This option does nothing at all; it is provided only for backwards
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Print timing statistics for
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If this option is used twice, additional timing statistics are printed
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on a pass by pass basis.
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Print version information and exit.
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Assume an answer of `yes' to all questions; allows
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to be used non-interactively. This option
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may not be specified at the same time as the
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The exit code returned by
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is the sum of the following conditions:
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\ 1\ \-\ File system errors corrected
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\ 2\ \-\ File system errors corrected, system should
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\ 4\ \-\ File system errors left uncorrected
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\ 8\ \-\ Operational error
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\ 16\ \-\ Usage or syntax error
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\ 32\ \-\ E2fsck canceled by user request
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\ 128\ \-\ Shared library error
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The following signals have the following effect when sent to
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to start displaying a completion bar or emitting progress information.
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(See discussion of the
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to stop displaying a completion bar or emitting progress information.
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Almost any piece of software will have bugs. If you manage to find a
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filesystem which causes
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is unable to repair, please report it to the author.
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Please include as much information as possible in your bug report.
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Ideally, include a complete transcript of the
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run, so I can see exactly what error messages are displayed. (Make sure
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the messages printed by
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are in English; if your system has been
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messages have been translated into another language, please set the the
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environment variable to
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so that the transcript of e2fsck's output will be useful to me.)
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have a writable filesystem where the transcript can be stored, the
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program is a handy way to save the output of
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It is also useful to send the output of
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If a specific inode or inodes seems to be giving
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trouble, try running the
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command and send the output of the
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command run on the relevant inode(s). If the inode is a directory, the
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command will allow you to extract the contents of the directory inode,
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which can sent to me after being first run through
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The most useful data you can send to help reproduce
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the bug is a compressed raw image dump of the filesystem, generated using
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man page for more details.
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Always include the full version string which
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displays when it is run, so I know which version you are running.
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was written by Theodore Ts'o <tytso@mit.edu>.
added
removed
e2fsprogs/C/man8/fsck.ext2.8
