10.2. Manual Page of e2fsck
e2fsck - check a Linux ext2/ext3 file system
e2fsck [ -pacnyrdfkvstDFSV ] [ -b superblock ] [ -B block-
size ] [ -l|-L bad_blocks_file ] [ -C fd ] [ -j external-
journal ] [ -E extended_options ] device
e2fsck is used to check a Linux second extended file system
(ext2fs). E2fsck also supports ext2 filesystems countain-
ing a journal, which are also sometimes known as ext3
filesystems, by first applying the journal to the filesys-
tem before continuing with normal e2fsck processing. After
the journal has been applied, a filesystem will normally be
marked as clean. Hence, for ext3 filesystems, e2fsck will
normally run the journal and exit, unless its superblock
indicates that further checking is required.
device is the device file where the filesystem is stored
-a This option does the same thing as the -p option.
It is provided for backwards compatibility only; it
is suggested that people use -p option whenever pos-
Instead of using the normal superblock, use an
alternative superblock specified by superblock.
This option is normally used when the primary
superblock has been corrupted. The location of the
backup superblock is dependent on the filesystem's
blocksize. For filesystems with 1k blocksizes, a
backup superblock can be found at block 8193; for
filesystems with 2k blocksizes, at block 16384; and
for 4k blocksizes, at block 32768.
Additional backup superblocks can be determined by
using the mke2fs program using the -n option to
print out where the superblocks were created. The
-b option to mke2fs, which specifies blocksize of
the filesystem must be specified in order for the
superblock locations that are printed out to be
If an alternative superblock is specified and the
filesystem is not opened read-only, e2fsck will make
sure that the primary superblock is updated appro-
priately upon completion of the filesystem check.
Normally, e2fsck will search for the superblock at
various different block sizes in an attempt to find
the appropriate block size. This search can be
fooled in some cases. This option forces e2fsck to
only try locating the superblock at a particular
blocksize. If the superblock is not found, e2fsck
will terminate with a fatal error.
-c This option causes e2fsck to run the badblocks(8)
program to find any blocks which are bad on the
filesystem, and then marks them as bad by adding
them to the bad block inode. If this option is
specified twice, then the bad block scan will be
done using a non-destructive read-write test.
-C fd This option causes e2fsck to write completion infor-
mation to the specified file descriptor so that the
progress of the filesystem check can be monitored.
This option is typically used by programs which are
running e2fsck. If the file descriptor specified is
0, e2fsck will print a completion bar as it goes
about its business. This requires that e2fsck is
running on a video console or terminal.
-d Print debugging output (useless unless you are
-D Optimize directories in filesystem. This option
causes e2fsck to try to optimize all directories,
either by reindexing them if the filesystem supports
directory indexing, or by sorting and compressing
directories for smaller directories, or for filesys-
tems using traditional linear directories.
Set e2fsck extended options. Extended options are
comma separated, and may take an argument using the
equals ('=') sign. The following options are sup-
Assume the format of the extended
attribute blocks in the filesystem is
the specified version number. The ver-
sion number may be 1 or 2. The default
extended attribute version format is 2.
-f Force checking even if the file system seems clean.
-F Flush the filesystem device's buffer caches before
beginning. Only really useful for doing e2fsck time
Set the pathname where the external-journal for this
filesystem can be found.
-k When combined with the -c option, any existing bad
blocks in the bad blocks list are preserved, and any
new bad blocks found by running badblocks(8) will be
added to the existing bad blocks list.
Add the block numbers listed in the file specified
by filename to the list of bad blocks. The format
of this file is the same as the one generated by the
badblocks(8) program. Note that the block numbers
are based on the blocksize of the filesystem.
Hence, badblocks(8) must be given the blocksize of
the filesystem in order to obtain correct results.
As a result, it is much simpler and safer to use the
-c option to e2fsck, since it will assure that the
correct parameters are passed to the badblocks pro-
Set the bad blocks list to be the list of blocks
specified by filename. (This option is the same as
the -l option, except the bad blocks list is cleared
before the blocks listed in the file are added to
the bad blocks list.)
-n Open the filesystem read-only, and assume an answer
of `no' to all questions. Allows e2fsck to be used
non-interactively. (Note: if the -c, -l, or -L
options are specified in addition to the -n option,
then the filesystem will be opened read-write, to
permit the bad-blocks list to be updated. However,
no other changes will be made to the filesystem.)
-p Automatically repair ("preen") the file system with-
out any questions.
-r This option does nothing at all; it is provided only
for backwards compatibility.
-s This option will byte-swap the filesystem so that it
is using the normalized, standard byte-order (which
is i386 or little endian). If the filesystem is
already in the standard byte-order, e2fsck will take
-S This option will byte-swap the filesystem, regard-
less of its current byte-order.
-t Print timing statistics for e2fsck. If this option
is used twice, additional timing statistics are
printed on a pass by pass basis.
-v Verbose mode.
-V Print version information and exit.
-y Assume an answer of `yes' to all questions; allows
e2fsck to be used non-interactively.
The exit code returned by e2fsck is the sum of the follow-
0 - No errors
1 - File system errors corrected
2 - File system errors corrected, system should
4 - File system errors left uncorrected
8 - Operational error
16 - Usage or syntax error
32 - E2fsck canceled by user request
128 - Shared library error
The following signals have the following effect when sent
This signal causes e2fsck to start displaying a com-
pletion bar. (See discussion of the -C option.)
This signal causes e2fsck to stop displaying a com-
Almost any piece of software will have bugs. If you manage
to find a filesystem which causes e2fsck to crash, or which
e2fsck is unable to repair, please report it to the author.
Please include as much information as possible in your bug
report. Ideally, include a complete transcript of the
e2fsck run, so I can see exactly what error messages are
displayed. If you have a writeable filesystem where the
transcript can be stored, the script(1) program is a handy
way to save the output of e2fsck to a file.
It is also useful to send the output of dumpe2fs(8). If a
specific inode or inodes seems to be giving e2fsck trouble,
try running the debugfs(8) command and send the output of
the stat(1u) command run on the relevant inode(s). If the
inode is a directory, the debugfs dump command will allow
you to extract the contents of the directory inode, which
can sent to me after being first run through uuencode(1).
Always include the full version string which e2fsck dis-
plays when it is run, so I know which version you are run-
This version of e2fsck was written by Theodore Ts'o
mke2fs(8), tune2fs(8), dumpe2fs(8), debugfs(8)
E2fsprogs version 1.36 February 2005 E2FSCK(8)