2 .\" Copyright 1993, 1994, 1995 by Theodore Ts'o. All Rights Reserved.
3 .\" This file may be copied under the terms of the GNU Public License.
5 .TH E2FSCK 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
7 e2fsck \- check a Linux ext2/ext3/ext4 file system
31 @JDEV@.I external-journal
40 is used to check the ext2/ext3/ext4 family of file systems.
41 For ext3 and ext4 filesystems that use a journal, if the system has been
42 shut down uncleanly without any errors, normally, after replaying the
43 committed transactions in the journal, the file system should be
44 marked as clean. Hence, for filesystems that use journalling,
46 will normally replay the journal and exit, unless its superblock
47 indicates that further checking is required.
50 is the device file where the filesystem is stored (e.g.
53 Note that in general it is not safe to run
55 on mounted filesystems. The only exception is if the
57 option is specified, and
64 specified. However, even if it is safe to do so, the results printed by
66 are not valid if the filesystem is mounted. If
68 asks whether or not you should check a filesystem which is mounted,
69 the only correct answer is ``no''. Only experts who really know what
70 they are doing should consider answering this question in any other way.
74 This option does the same thing as the
76 option. It is provided for backwards compatibility only; it is
77 suggested that people use
79 option whenever possible.
82 Instead of using the normal superblock, use an alternative superblock
85 This option is normally used when the primary superblock has been
86 corrupted. The location of the backup superblock is dependent on the
87 filesystem's blocksize. For filesystems with 1k blocksizes, a backup
88 superblock can be found at block 8193; for filesystems with 2k
89 blocksizes, at block 16384; and for 4k blocksizes, at block 32768.
91 Additional backup superblocks can be determined by using the
95 option to print out where the superblocks were created. The
99 which specifies blocksize of the filesystem must be specified in order
100 for the superblock locations that are printed out to be accurate.
102 If an alternative superblock is specified and
103 the filesystem is not opened read-only, e2fsck will make sure that the
104 primary superblock is updated appropriately upon completion of the
110 will search for the superblock at various different
111 block sizes in an attempt to find the appropriate block size.
112 This search can be fooled in some cases. This option forces
114 to only try locating the superblock at a particular blocksize.
115 If the superblock is not found,
117 will terminate with a fatal error.
124 program to do a read-only scan of the device in order to find any bad
125 blocks. If any bad blocks are found, they are added to the bad block
126 inode to prevent them from being allocated to a file or directory. If
127 this option is specified twice, then the bad block scan will be done
128 using a non-destructive read-write test.
133 to write completion information to the specified file descriptor
134 so that the progress of the filesystem
135 check can be monitored. This option is typically used by programs
138 If the file descriptor number is negative, then absolute value of
139 the file descriptor will be used, and the progress information will be
140 suppressed initially. It can later be enabled by sending the
142 process a SIGUSR1 signal.
143 If the file descriptor specified is 0,
145 will print a completion bar as it goes about its business. This requires
146 that e2fsck is running on a video console or terminal.
149 Print debugging output (useless unless you are debugging
153 Optimize directories in filesystem. This option causes e2fsck to
154 try to optimize all directories, either by reindexing them if the
155 filesystem supports directory indexing, or by sorting and compressing
156 directories for smaller directories, or for filesystems using
157 traditional linear directories.
163 may sometimes optimize a few directories --- for example, if
164 directory indexing is enabled and a directory is not indexed and would
165 benefit from being indexed, or if the index structures are corrupted
166 and need to be rebuilt. The
168 option forces all directories in the filesystem to be optimized. This can
169 sometimes make them a little smaller and slightly faster to search, but
170 in practice, you should rarely need to use this option.
174 option will detect directory entries with duplicate names in a single
175 directory, which e2fsck normally does not enforce for performance reasons.
177 .BI \-E " extended_options"
178 Set e2fsck extended options. Extended options are comma
179 separated, and may take an argument using the equals ('=') sign. The
180 following options are supported:
183 .BI ea_ver= extended_attribute_version
184 Set the version of the extended attribute blocks which
186 will require while checking the filesystem. The version number may
187 be 1 or 2. The default extended attribute version format is 2.
190 During pass 1, print a detailed report of any discontiguous blocks for
191 files in the filesystem.
194 Attempt to discard free blocks and unused inode blocks after the full
195 filesystem check (discarding blocks is useful on solid state devices and sparse
196 / thin-provisioned storage). Note that discard is done in pass 5 AFTER the
197 filesystem has been fully checked and only if it does not contain recognizable
198 errors. However there might be cases where
200 does not fully recognise a problem and hence in this case this
201 option may prevent you from further manual data recovery.
204 Do not attempt to discard free blocks and unused inode blocks. This option is
205 exacly the opposite of discard option. This is set as default.
209 Force checking even if the file system seems clean.
212 Flush the filesystem device's buffer caches before beginning. Only
213 really useful for doing
217 @JDEV@.BI \-j " external-journal"
218 @JDEV@Set the pathname where the external-journal for this filesystem can be
222 When combined with the
224 option, any existing bad blocks in the bad blocks list are preserved,
225 and any new bad blocks found by running
227 will be added to the existing bad blocks list.
230 Add the block numbers listed in the file specified by
232 to the list of bad blocks. The format of this file is the same as the
235 program. Note that the block numbers are based on the blocksize
236 of the filesystem. Hence,
238 must be given the blocksize of the filesystem in order to obtain correct
239 results. As a result, it is much simpler and safer to use the
243 since it will assure that the correct parameters are passed to the
248 Set the bad blocks list to be the list of blocks specified by
250 (This option is the same as the
252 option, except the bad blocks list is cleared before the blocks listed
253 in the file are added to the bad blocks list.)
256 Open the filesystem read-only, and assume an answer of `no' to all
259 to be used non-interactively. This option
260 may not be specified at the same time as the
267 Automatically repair ("preen") the file system. This option will cause
270 fix any filesystem problems that can be safely fixed without human
273 discovers a problem which may require the system administrator
274 to take additional corrective action,
276 will print a description of the problem and then exit with the value 4
277 logically or'ed into the exit code. (See the \fBEXIT CODE\fR section.)
278 This option is normally used by the system's boot scripts. It may not
279 be specified at the same time as the
286 This option does nothing at all; it is provided only for backwards
290 Print timing statistics for
292 If this option is used twice, additional timing statistics are printed
293 on a pass by pass basis.
299 Print version information and exit.
302 Assume an answer of `yes' to all questions; allows
304 to be used non-interactively. This option
305 may not be specified at the same time as the
311 The exit code returned by
313 is the sum of the following conditions:
317 \ 1\ \-\ File system errors corrected
319 \ 2\ \-\ File system errors corrected, system should
323 \ 4\ \-\ File system errors left uncorrected
325 \ 8\ \-\ Operational error
327 \ 16\ \-\ Usage or syntax error
329 \ 32\ \-\ E2fsck canceled by user request
331 \ 128\ \-\ Shared library error
334 The following signals have the following effect when sent to
340 to start displaying a completion bar or emitting progress information.
341 (See discussion of the
348 to stop displaying a completion bar or emitting progress information.
350 Almost any piece of software will have bugs. If you manage to find a
351 filesystem which causes
355 is unable to repair, please report it to the author.
357 Please include as much information as possible in your bug report.
358 Ideally, include a complete transcript of the
360 run, so I can see exactly what error messages are displayed. (Make sure
361 the messages printed by
363 are in English; if your system has been
366 messages have been translated into another language, please set the the
368 environment variable to
370 so that the transcript of e2fsck's output will be useful to me.)
372 have a writable filesystem where the transcript can be stored, the
374 program is a handy way to save the output of
378 It is also useful to send the output of
380 If a specific inode or inodes seems to be giving
382 trouble, try running the
384 command and send the output of the
386 command run on the relevant inode(s). If the inode is a directory, the
389 command will allow you to extract the contents of the directory inode,
390 which can sent to me after being first run through
392 The most useful data you can send to help reproduce
393 the bug is a compressed raw image dump of the filesystem, generated using
397 man page for more details.
399 Always include the full version string which
401 displays when it is run, so I know which version you are running.
405 was written by Theodore Ts'o <tytso@mit.edu>.
git://git.whamcloud.com / tools / e2fsprogs.git / blob