10.2. Manual Page of e2fsck

E2FSCK(8)                                                E2FSCK(8)

       e2fsck - check a Linux ext2/ext3 file system

       e2fsck  [ -pacnyrdfkvstDFSV ] [ -b superblock ] [ -B block-
       size ] [ -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  countain-
       ing  a  journal,  which  are  also  sometimes known as ext3
       filesystems, by first applying the journal to the  filesys-
       tem 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).

       -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 pos-

       -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

              If  an  alternative  superblock is specified and the
              filesystem is not opened read-only, e2fsck will make
              sure  that  the primary superblock is updated appro-
              priately 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 fd  This option causes e2fsck to write completion infor-
              mation 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 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  separated, and may take an argument using the
              equals ('=') sign.  The following options  are  sup-

                          Assume   the   format  of  the  extended
                          attribute blocks in  the  filesystem  is
                          the  specified version number.  The ver-
                          sion 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

       -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  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  pro-

       -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 with-
              out 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 filesystem 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.

       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
            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 com-
              pletion bar.  (See discussion of the -C option.)

              This signal causes e2fsck to stop displaying a  com-
              pletion 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 dis-
       plays when it is run, so I know which version you are  run-

       This  version  of  e2fsck  was  written  by  Theodore  Ts'o

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

E2fsprogs version 1.36     February 2005                 E2FSCK(8)