Manual Page of e2fsck

E2FSCK(8) E2FSCK(8) NAME e2fsck - check a Linux second extended file system SYNOPSIS e2fsck [ -pacnyrdfvstFSV ] [ -b superblock ] [ -B block- size ] [ -l|-L bad_blocks_file ] [ -C fd ] [ -j external- journal ] [ device DESCRIPTION e2fsck is used to check a Linux second extended file sys- tem (e2fs). E2fsck also supports ext2 filesystems coun- taining a journal, which are also sometimes known as ext3 filesystems. device is the special file corresponding to the device (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. -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 pro- grams which are running e2fsck. If the file descriptor specified is 0, e2fsck will print a com- pletion 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 blocks 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. -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 ("preen") the file system without any questions. -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 filesys- tem is already in the standard byte-order, e2fsck will take no action. -S This option will byte-swap the filesystem, regard- less 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 follow- ing 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 com- pletion bar. REPORTING BUGS Almost any piece of software will have bugs. If you man- age 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 trou- ble, try running the debugfs(8) command and send the out- put 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 uuen� code(1). Always include the full version string which e2fsck dis- plays when it is run, so I know which version you are run- ning. AUTHOR This version of e2fsck was written by Theodore Ts'o <tytso@mit.edu>. SEE ALSO mke2fs(8), tune2fs(8), dumpe2fs(8), debugfs(8) E2fsprogs version 1.25 September 2001 E2FSCK(8)