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E2FSCK(8)                   System Manager's Manual                  E2FSCK(8)



NAME
       e2fsck - check a Linux ext2/ext3 file system

SYNOPSIS
       e2fsck [ -pacnyrdfkvstDFSV ] [ -b superblock ] [ -B blocksize ] [ -l|-L
       bad_blocks_file  ]  [  -C  fd  ]  [  -j   external-journal   ]   [   -E
       extended_options ] device

DESCRIPTION
       e2fsck  is  used to check a Linux second extended file system (ext2fs).
       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  e2fsck  processing.
       After  the  journal  has  been  applied,  a filesystem will normally be
       marked as clean.  Hence, for ext3 filesystems, e2fsck will normally run
       the  journal  and  exit,  unless  its superblock indicates that further
       checking is required.

       device is  the  device  file  where  the  filesystem  is  stored  (e.g.
       /dev/hdc1).

OPTIONS
       -a     This  option  does  the same thing as the -p option.  It is pro-
              vided 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 loca-
              tion 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 spec-
              ifies 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 dif-
              ferent 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  particu-
              lar blocksize.  If the superblock is not found, e2fsck will ter-
              minate 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 fd  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 speci-
              fied 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
              e2fsck).

       -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 filesys-
              tems using traditional linear directories.

       -E extended_options
              Set  e2fsck  extended options.  Extended options are comma sepa-
              rated, and may take an argument using  the  equals  ('=')  sign.
              The following options are supported:

                   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.

       -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.

       -k     When combined with the -c option, any existing bad blocks in the
              bad  blocks  list are preserved, and any new bad blocks found by
              running badblocks(8) will be added to the  existing  bad  blocks
              list.

       -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 filesys-
              tem 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
              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 ques-
              tions.

       -r     This option does nothing at all; it is provided only  for  back-
              wards 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  filesystem  is already in the standard byte-
              order, 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
       The exit code returned by e2fsck is the sum  of  the  following  condi-
       tions:
            0    - No errors
            1    - File system errors corrected
            2    - File system errors corrected, system should
                   be rebooted
            4    - File system errors left uncorrected
            8    - Operational error
            16   - Usage or syntax error
            32   - E2fsck canceled by user request
            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 completion bar.

REPORTING BUGS
       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
       This version of e2fsck was written by Theodore Ts'o <tytsoATmit.edu>.

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



E2fsprogs version 1.37            March 2005                         E2FSCK(8)