E2FSCK linux command manual

E2FSCK(8)                                                      E2FSCK(8)

       e2fsck - check a Linux ext2/ext3 file system

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

       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 jour-
       nal 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.

       -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

              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

              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
              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 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  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

       -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
              filesystems 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:

                          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 bad-
              blocks 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

       -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.

       The  exit  code  returned by e2fsck is the sum of the following condi-
            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

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

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

              This  signal causes e2fsck to stop displaying a completion bar.

       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.

       This version of e2fsck was written by Theodore Ts'o .

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

E2fsprogs version 1.35          February 2004                       E2FSCK(8)