View Source: fsck.ext2(8) - Waikato Linux Users Group

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E2FSCK
!!!E2FSCK
NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXIT CODE
SIGNALS
REPORTING BUGS
AUTHOR
SEE ALSO
----
!!NAME


e2fsck - check a Linux second extended file system
!!SYNOPSIS


__e2fsck__ [[ __-pacnyrdfvstFSV__ ] [[ __-b__
''superblock'' ] [[ __-B__ ''blocksize'' ] [[
__-l__|__-L__ ''bad_blocks_file'' ] [[ __-C__
''fd'' ] [[ __-j__ ''external-journal'' ]
''device''
!!DESCRIPTION


__e2fsck__ is used to check a Linux second extended file
system (e2fs). E2fsck also supports ext2 filesystems
countaining a journal, which are also sometimes known as
ext3 filesystems.


''device'' is the device file where the filesystem is
stored (e.g. ''/dev/hdc1'').
!!OPTIONS


__-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
possible.


__-b__ ''superblock''


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 accurate.


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 filesystem check.


__-B__ ''blocksize''


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__


This option causes __e2fsck__ 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
__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 debugging
__e2fsck__).


__-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
trials.


__-j__ ''external-journal''


Set the pathname where the external-journal for this
filesystem can be found.


__-l__ ''filename''


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__
program.


__-L__ ''filename''


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 (


__-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 no action.


__-S__


This option will byte-swap the filesystem, regardless 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.
!!EXIT CODE


The exit code returned by __e2fsck__ 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
!!SIGNALS


The following signals have the following effect when sent to
__e2fsck__.


__SIGUSR1__


This signal causes __e2fsck__ to start displaying a
completion bar. (See discussion of the __-C__
option.)


__SIGUSR2__


This signal causes __e2fsck__ to stop displaying a
completion bar.
!!REPORTING BUGS


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__
displays when it is run, so I know which version you are
running.
!!AUTHOR


This version of __e2fsck__ was written by Theodore Ts'o
__
!!SEE ALSO


mke2fs(8), __tune2fs__(8), __dumpe2fs__(8),
debugfs(8)
----
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Last edited on Tuesday, June 4, 2002 12:31:12 am by "perry"
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