path: root/e2fsck/e2fsck.8.in

.\" -*- nroff -*-
.\" Copyright 1993, 1994, 1995 by Theodore Ts'o.  All Rights Reserved.
.\" This file may be copied under the terms of the GNU Public License.
.\" 
.TH E2FSCK 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
e2fsck \- check a Linux second extended file system
.SH SYNOPSIS
.B e2fsck
[
.B \-pacnyrdfvstDFSV
]
[
.B \-b
.I superblock
]
[
.B \-B
.I blocksize
]
[
.BR \-l | \-L
.I bad_blocks_file
]
[
.B \-C
.I fd
]
@JDEV@[
@JDEV@.B \-j
@JDEV@.I external-journal
@JDEV@]
[
.B \-E
.I extended_options
]
.I device
.SH DESCRIPTION
.B e2fsck
is used to check a Linux second extended file system (ext2fs).  
.B E2fsck
also 
supports ext2 filesystems countaining a journal, which are
also sometimes known as ext3 filesystems, by first applying the journal 
to the filesystem before continuing with normal 
.B e2fsck
processing.  After the journal has been applied, a filesystem will
normally be marked as clean.  Hence, for ext3 filesystems, 
.B e2fsck
will normally run the journal and exit, unless its superblock
indicates that further checking is required.
.PP
.I device
is the device file where the filesystem is stored (e.g.
.IR /dev/hdc1 ).
.SH OPTIONS
.TP
.B \-a 
This option does the same thing as the 
.B \-p
option.  It is provided for backwards compatibility only; it is
suggested that people use 
.B \-p 
option whenever possible.
.TP
.BI \-b " superblock"
Instead of using the normal superblock, use an alternative superblock
specified by 
.IR 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.  
.IP
Additional backup superblocks can be determined by using the 
.B mke2fs 
program using the 
.B \-n
option to print out where the superblocks were created.   The 
.B \-b 
option to 
.BR mke2fs ,
which specifies blocksize of the filesystem must be specified in order
for the superblock locations that are printed out to be accurate.
.IP
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.
.TP
.BI \-B " blocksize"
Normally, 
.B 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 
.B e2fsck
to only try locating the superblock at a particular blocksize.
If the superblock is not found, 
.B e2fsck 
will terminate with a fatal error.
.TP
.B \-c
This option causes 
.B e2fsck 
to run the 
.BR 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.
.TP
.B \-C
This option causes
.B 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
.BR e2fsck .
If the file descriptor specified is 0, 
.B e2fsck
will print a completion bar as it goes about its business.  This requires
that e2fsck is running on a video console or terminal.
.TP
.B \-d
Print debugging output (useless unless you are debugging
.BR e2fsck ).
.TP
.B \-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 filesystems using
traditional linear directories.
.TP
.BI \-E " extended_options"
Set e2fsck extended options.  Extended options are comma
separated, and may take an argument using the equals ('=') sign.  The 
following options are supported:
.RS 1.2i
.TP
.BI ea_ver= extended_attribute_version
Assume the format of the extended attribute blocks in the filesystem is
the specified version number.  The version number may be 1 or 2.  The
default extended attribute version format is 2.
.RE
.TP
.B \-f
Force checking even if the file system seems clean.
.TP
.B \-F
Flush the filesystem device's buffer caches before beginning.  Only
really useful for doing 
.B e2fsck 
time trials.
@JDEV@.TP
@JDEV@.BI \-j " external-journal"
@JDEV@Set the pathname where the external-journal for this filesystem can be
@JDEV@found.
.TP
.BI \-l " filename"
Add the block numbers listed in the file specified by 
.I filename
to the list of bad blocks.  The format of this file is the same as the
one generated by the 
.BR badblocks (8)
program.  Note that the block numbers are based on the blocksize
of the filesystem.  Hence, 
.BR 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 
.B -c
option to 
.BR e2fsck ,
since it will assure that the correct parameters are passed to the
.B badblocks
program.
.TP
.BI \-L " filename"
Set the bad blocks list to be the list of blocks specified by 
.IR filename .
(This option is the same as the 
.B \-l
option, except the bad blocks list is cleared before the blocks listed
in the file are added to the bad blocks list.)
.TP
.B \-n
Open the filesystem read-only, and assume an answer of `no' to all
questions.  Allows
.B e2fsck
to be used non-interactively.  (Note: if the 
.BR \-c ,
.BR \-l ,
or
.B \-L
options are specified in addition to the 
.B \-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.)
.TP
.B \-p
Automatically repair ("preen") the file system without any questions.
.TP
.B \-r
This option does nothing at all; it is provided only for backwards
compatibility.
.TP 
.B \-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, 
.B e2fsck 
will take no action.
.TP
.B \-S
This option will byte-swap the filesystem, regardless of its current 
byte-order.
.TP
.B \-t
Print timing statistics for
.BR e2fsck .
If this option is used twice, additional timing statistics are printed
on a pass by pass basis.
.TP
.B \-v
Verbose mode.
.TP
.B \-V
Print version information and exit.
.TP
.B \-y
Assume an answer of `yes' to all questions; allows 
.B e2fsck
to be used non-interactively.
.SH EXIT CODE
The exit code returned by
.B e2fsck
is the sum of the following conditions:
.br
\	0\	\-\ No errors
.br
\	1\	\-\ File system errors corrected
.br
\	2\	\-\ File system errors corrected, system should
.br
\	\	\ \ be rebooted
.br
\	4\	\-\ File system errors left uncorrected
.br
\	8\	\-\ Operational error
.br
\	16\	\-\ Usage or syntax error
.br
\	32\	\-\ E2fsck canceled by user request
.br
\	128\	\-\ Shared library error
.br
.SH SIGNALS
The following signals have the following effect when sent to 
.BR e2fsck .
.TP
.B SIGUSR1
This signal causes
.B e2fsck
to start displaying a completion bar.  (See discussion of the 
.B \-C
option.)
.TP
.B SIGUSR2
This signal causes
.B e2fsck 
to stop displaying a completion bar.
.SH REPORTING BUGS
Almost any piece of software will have bugs.  If you manage to find a
filesystem which causes 
.B e2fsck
to crash, or which 
.B e2fsck
is unable to repair, please report it to the author.
.PP
Please include as much information as possible in your bug report.
Ideally, include a complete transcript of the
.B 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 
.BR script (1)
program is a handy way to save the output of
.B e2fsck
to a file.
.PP
It is also useful to send the output of 
.BR dumpe2fs (8).
If a specific inode or inodes seems to be giving 
.B e2fsck 
trouble, try running the
.BR debugfs (8)
command and send the output of the 
.BR stat (1u)
command run on the relevant inode(s).  If the inode is a directory, the 
.B debugfs
.I dump
command will allow you to extract the contents of the directory inode,
which can sent to me after being first run through
.BR uuencode (1).
.PP
Always include the full version string which 
.B e2fsck
displays when it is run, so I know which version you are running.
.SH AUTHOR
This version of 
.B e2fsck
was written by Theodore Ts'o <tytso@mit.edu>.
.SH SEE ALSO
.BR mke2fs (8),
.BR tune2fs (8),
.BR dumpe2fs (8),
.BR debugfs (8)