1E2FSCK(8) System Manager's Manual E2FSCK(8)
2
6 e2fsck - check a Linux ext2/ext3 file system
7
9 e2fsck [ -pacnyrdfkvstDFSV ] [ -b superblock ] [ -B blocksize ] [ -l|-L
10 bad_blocks_file ] [ -C fd ] [ -j external-journal ] [ -E
11 extended_options ] device
12
14 e2fsck is used to check a Linux second extended file system (ext2fs).
15 E2fsck also supports ext2 filesystems containing a journal, which are
16 also sometimes known as ext3 filesystems, by first applying the journal
17 to the filesystem before continuing with normal e2fsck processing.
18 After the journal has been applied, a filesystem will normally be
19 marked as clean. Hence, for ext3 filesystems, e2fsck will normally run
20 the journal and exit, unless its superblock indicates that further
21 checking is required.
22 device is the device file where the filesystem is stored (e.g.
24 /dev/hdc1).
25 Note that in general it is not safe to run e2fsck on mounted filesys‐
27 tems. The only exception is if the -n option is specified, and -c, -l,
28 or -L options are not specified. However, even if it is safe to do
29 so, the results printed by e2fsck are not valid if the filesystem is
30 mounted. If e2fsck asks whether or not you should check a filesystem
31 which is mounted, the only correct answer is ``no''. Only experts who
32 really know what they are doing should consider answering this question
33 in any other way.
34
36 -a This option does the same thing as the -p option. It is pro‐
37 vided for backwards compatibility only; it is suggested that
38 people use -p option whenever possible.
39 -b superblock
41 Instead of using the normal superblock, use an alternative
42 superblock specified by superblock. This option is normally
43 used when the primary superblock has been corrupted. The loca‐
44 tion of the backup superblock is dependent on the filesystem's
45 blocksize. For filesystems with 1k blocksizes, a backup
46 superblock can be found at block 8193; for filesystems with 2k
47 blocksizes, at block 16384; and for 4k blocksizes, at block
48 32768.
49 Additional backup superblocks can be determined by using the
51 mke2fs program using the -n option to print out where the
52 superblocks were created. The -b option to mke2fs, which spec‐
53 ifies blocksize of the filesystem must be specified in order for
54 the superblock locations that are printed out to be accurate.
55 If an alternative superblock is specified and the filesystem is
57 not opened read-only, e2fsck will make sure that the primary
58 superblock is updated appropriately upon completion of the
59 filesystem check.
60 -B blocksize
62 Normally, e2fsck will search for the superblock at various dif‐
63 ferent block sizes in an attempt to find the appropriate block
64 size. This search can be fooled in some cases. This option
65 forces e2fsck to only try locating the superblock at a particu‐
66 lar blocksize. If the superblock is not found, e2fsck will ter‐
67 minate with a fatal error.
68 -c This option causes e2fsck to use badblocks(8) program to do a
70 read-only scan of the device in order to find any bad blocks.
71 If any bad blocks are found, they are added to the bad block
72 inode to prevent them from being allocated to a file or direc‐
73 tory. If this option is specified twice, then the bad block
74 scan will be done using a non-destructive read-write test.
75 -C fd This option causes e2fsck to write completion information to the
77 specified file descriptor so that the progress of the filesystem
78 check can be monitored. This option is typically used by pro‐
79 grams which are running e2fsck. If the file descriptor speci‐
80 fied is 0, e2fsck will print a completion bar as it goes about
81 its business. This requires that e2fsck is running on a video
82 console or terminal.
83 -d Print debugging output (useless unless you are debugging
85 e2fsck).
86 -D Optimize directories in filesystem. This option causes e2fsck
88 to try to optimize all directories, either by reindexing them if
89 the filesystem supports directory indexing, or by sorting and
90 compressing directories for smaller directories, or for filesys‐
91 tems using traditional linear directories.
92 -E extended_options
94 Set e2fsck extended options. Extended options are comma sepa‐
95 rated, and may take an argument using the equals ('=') sign.
96 The following options are supported:
97 ea_ver=extended_attribute_version
99 Assume the format of the extended attribute blocks
100 in the filesystem is the specified version number.
101 The version number may be 1 or 2. The default
102 extended attribute version format is 2.
103 -f Force checking even if the file system seems clean.
105 -F Flush the filesystem device's buffer caches before beginning.
107 Only really useful for doing e2fsck time trials.
108 -j external-journal
110 Set the pathname where the external-journal for this filesystem
111 can be found.
112 -k When combined with the -c option, any existing bad blocks in the
114 bad blocks list are preserved, and any new bad blocks found by
115 running badblocks(8) will be added to the existing bad blocks
116 list.
117 -l filename
119 Add the block numbers listed in the file specified by filename
120 to the list of bad blocks. The format of this file is the same
121 as the one generated by the badblocks(8) program. Note that the
122 block numbers are based on the blocksize of the filesystem.
123 Hence, badblocks(8) must be given the blocksize of the filesys‐
124 tem in order to obtain correct results. As a result, it is much
125 simpler and safer to use the -c option to e2fsck, since it will
126 assure that the correct parameters are passed to the badblocks
127 program.
128 -L filename
130 Set the bad blocks list to be the list of blocks specified by
131 filename. (This option is the same as the -l option, except the
132 bad blocks list is cleared before the blocks listed in the file
133 are added to the bad blocks list.)
134 -n Open the filesystem read-only, and assume an answer of `no' to
136 all questions. Allows e2fsck to be used non-interactively.
137 (Note: if the -c, -l, or -L options are specified in addition to
138 the -n option, then the filesystem will be opened read-write, to
139 permit the bad-blocks list to be updated. However, no other
140 changes will be made to the filesystem.) This option may not be
141 specified at the same time as the -p or -y options.
142 -p Automatically repair ("preen") the file system. This option
144 will case e2fsck to automatically fix any filesystem problems
145 that can be safely fixed without human intervention. If e2fsck
146 discovers a problem which may require the system administrator
147 to take additional corrective action, e2fsck will print a
148 description of the problem and then exit with the value 4 logi‐
149 cally or'ed into the exit code. (See the EXIT CODE section.)
150 This option is normally used by the system's boot scripts. It
151 may not be specified at the same time as the -n or -y options.
152 -r This option does nothing at all; it is provided only for back‐
154 wards compatibility.
155 -s This option will byte-swap the filesystem so that it is using
157 the normalized, standard byte-order (which is i386 or little
158 endian). If the filesystem is already in the standard byte-
159 order, e2fsck will take no action.
160 -S This option will byte-swap the filesystem, regardless of its
162 current byte-order.
163 -t Print timing statistics for e2fsck. If this option is used
165 twice, additional timing statistics are printed on a pass by
166 pass basis.
167 -v Verbose mode.
169 -V Print version information and exit.
171 -y Assume an answer of `yes' to all questions; allows e2fsck to be
173 used non-interactively. This option may not be specified at the
174 same time as the -n or -p options.
175
177 The exit code returned by e2fsck is the sum of the following condi‐
178 tions:
179 0 - No errors
180 1 - File system errors corrected
181 2 - File system errors corrected, system should
182 be rebooted
183 4 - File system errors left uncorrected
184 8 - Operational error
185 16 - Usage or syntax error
186 32 - E2fsck canceled by user request
187 128 - Shared library error
188
190 The following signals have the following effect when sent to e2fsck.
191 SIGUSR1
193 This signal causes e2fsck to start displaying a completion bar.
194 (See discussion of the -C option.)
195 SIGUSR2
197 This signal causes e2fsck to stop displaying a completion bar.
198
200 Almost any piece of software will have bugs. If you manage to find a
201 filesystem which causes e2fsck to crash, or which e2fsck is unable to
202 repair, please report it to the author.
203 Please include as much information as possible in your bug report.
205 Ideally, include a complete transcript of the e2fsck run, so I can see
206 exactly what error messages are displayed. (Make sure the messages
207 printed by e2fsck are in English; if your system has been configured so
208 that e2fsck's messages have been translated into another language,
209 please set the the LC_ALL environment variable to C so that the tran‐
210 script of e2fsck's output will be useful to me.) If you have a
211 writable filesystem where the transcript can be stored, the script(1)
212 program is a handy way to save the output of e2fsck to a file.
213 It is also useful to send the output of dumpe2fs(8). If a specific
215 inode or inodes seems to be giving e2fsck trouble, try running the
216 debugfs(8) command and send the output of the stat(1u) command run on
217 the relevant inode(s). If the inode is a directory, the debugfs dump
218 command will allow you to extract the contents of the directory inode,
219 which can sent to me after being first run through uuencode(1). The
220 most useful data you can send to help reproduce the bug is a compressed
221 raw image dump of the filesystem, generated using e2image(8). See the
222 e2image(8) man page for more details.
223 Always include the full version string which e2fsck displays when it is
225 run, so I know which version you are running.
226
228 This version of e2fsck was written by Theodore Ts'o <tytso@mit.edu>.
229
231 badblocks(8), dumpe2fs(8), debugfs(8), e2image(8), mke2fs(8),
232 tune2fs(8)
233E2fsprogs version 1.40.2 July 2007 E2FSCK(8)