Section: Maintenance Commands (8)
Updated: July 2000Index
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Copyright 1993, 1994, 1995 by Theodore Ts'o. All Rights Reserved.
This file may be copied under the terms of the GNU Public License.
e2fsck - check a Linux second extended file system
is used to check a Linux second extended file system.
is the special file corresponding to the device (e.g
This option does the same thing as the
option. It is provided for backwards compatibility only; it is
suggested that people use
option whenever possible.
- -b superblock
Instead of using the normal superblock, use an alternative 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. If
an alternative superblock is specified and
the filesystem is not opened read-only, e2fsck will make sure that the
primary superblock is updated appropriately upon completion of the
- -B blocksize
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
to only try locating the superblock at a particular blocksize.
If the superblock is not found,
will terminate with a fatal error.
This option causes
to run the
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.
This option causes
to write completion information 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
If the file descriptor specified is 0,
will print a completion bar as it goes about its business. This requires
that e2fsck is running on a video console or terminal.
Print debugging output (useless unless you are debugging
Force checking even if the file system seems clean.
Flush the filesystem device's buffer caches before beginning. Only
really useful for doing
- -l filename
Add the blocks listed in the file specified by
to the list of bad blocks. The format of this file is the same as the
one generated by the
- -L filename
Set the bad blocks list to be the list of blocks specified by
(This option is the same as the
option, except the bad blocks list is cleared before the blocks listed
in the file are added to the bad blocks list.)
Open the filesystem read-only, and assume an answer of `no' to all
to be used non-interactively. (Note: if the
options are specified in addition to the
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.)
Automatically repair ("preen") the file system without any questions.
This option does nothing at all; it is provided only for backwards
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,
will take no action.
This option will byte-swap the filesystem, regardless of its current
Print timing statistics for
If this option is used twice, additional timing statistics are printed
on a pass by pass basis.
Print version information and exit.
Assume an answer of `yes' to all questions; allows
to be used non-interactively.
The exit code returned by
is the sum of the following conditions:
0 - No errors
1 - File system errors corrected
2 - File system errors corrected, system should
be rebooted if file system was mounted
4 - File system errors left uncorrected
8 - Operational error
16 - Usage or syntax error
128 - Shared library error
The following signals have the following effect when sent to
This signal causes
to start displaying a completion bar. (See discussion of the
This signal causes
to stop displaying a completion bar.
Almost any piece of software will have bugs. If you manage to find a
filesystem which causes
to crash, or which
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
run, so I can see exactly what error messages are displayed. If you
have a writeable filesystem where the transcript can be stored, the
program is a handy way to save the output of
to a file.
It is also useful to send the output of
If a specific inode or inodes seems to be giving
trouble, try running the
command and send the output of the
command run on the relevant inode(s). If the inode is a directory, the
command will allow you to extract the contents of the directory inode,
which can sent to me after being first run through
Always include the full version string which
displays when it is run, so I know which version you are running.
This version of
was written by Theodore Ts'o <email@example.com
- EXIT CODE
- REPORTING BUGS
- SEE ALSO