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NAME    [Toc]    [Back]

       e2fsck - check a Linux second extended file system

SYNOPSIS    [Toc]    [Back]

       e2fsck  [  -pacnyrdfvstFSV ] [ -b superblock ] [ -B blocksize ] [ -l|-L
       bad_blocks_file ] [ -C fd ] [ -j external-journal ] device

DESCRIPTION    [Toc]    [Back]

       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.

OPTIONS    [Toc]    [Back]

       -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

	      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

       -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

       -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

       -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 byteorder,
 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    [Toc]    [Back]

       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    [Toc]    [Back]

       The following signals have the following effect when sent to e2fsck.

       SIGUSR1    [Toc]    [Back]
	      This  signal causes e2fsck to start displaying a completion bar.
	      (See discussion of the -C option.)

       SIGUSR2    [Toc]    [Back]
	      This signal causes e2fsck to stop displaying a completion bar.

REPORTING BUGS    [Toc]    [Back]

       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    [Toc]    [Back]

       This version of e2fsck was written by Theodore Ts'o <tytso@mit.edu>.

SEE ALSO    [Toc]    [Back]

       mke2fs(8), tune2fs(8), dumpe2fs(8), debugfs(8)

E2fsprogs version 1.27		  March 2002			     E2FSCK(8)
[ Back ]
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