Provided by: e2fsprogs_1.40.8-2ubuntu2_i386 bug

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 containing 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).

       Note  that  in  general  it  is  not  safe  to  run  e2fsck  on mounted
       filesystems.  The only exception is if the -n option is specified,  and
       -c,  -l, or -L options are not specified.   However, even if it is safe
       to do so, the results printed by e2fsck are not valid if the filesystem
       is  mounted.    If  e2fsck  asks  whether  or  not  you  should check a
       filesystem which is mounted, the only correct answer is  ‘‘no’’.   Only
       experts  who  really know what they are doing should consider answering
       this question in any other way.

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 use badblocks(8) program  to  do  a
              read-only  scan  of  the device in order to find any bad blocks.
              If any bad blocks are found, they are added  to  the  bad  block
              inode  to  prevent  them  from  being  allocated  to  a  file or
              directory.  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
              number is negative, then absolute value of the  file  descriptor
              will  be  used,  and the progress information will be suppressed
              initially.  It can  later  be  enabled  by  sending  the  e2fsck
              process  a  SIGUSR1 signal.  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
              filesystems using traditional linear directories.

              Even  without the -D option, e2fsck may sometimes optimize a few
              directories --- for example, if directory  indexing  is  enabled
              and  a  directory  is  not  indexed and would benefit from being
              indexed, or if the index structures are corrupted and need to be
              rebuilt.  The -D option forces all directories in the filesystem
              to be optimized.  This can sometimes make them a little  smaller
              and  slightly  faster  to  search,  but  in practice, you should
              rarely need to use this option.

              The -D option will detect directory entries with duplicate names
              in  a  single  directory, which e2fsck normally does not enforce
              for performance reasons.

       -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 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
              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 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.)  This option may not be
              specified at the same time as the -p or -y options.

       -p     Automatically  repair  ("preen")  the  file system.  This option
              will case e2fsck to automatically fix  any  filesystem  problems
              that  can be safely fixed without human intervention.  If e2fsck
              discovers a problem which may require the  system  administrator
              to  take  additional  corrective  action,  e2fsck  will  print a
              description of the problem  and  then  exit  with  the  value  4
              logically  or’ed  into  the  exit  code.   (See  the  EXIT  CODE
              section.)  This option is normally used  by  the  system’s  boot
              scripts.   It may not be specified at the same time as the -n or
              -y options.

       -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,  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.  This option may not be specified at the
              same time as the -n or -p options.

EXIT CODE

       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
            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
              or  emitting  progress  information.   (See discussion of the -C
              option.)

       SIGUSR2
              This signal causes e2fsck to stop displaying a completion bar or
              emitting progress information.

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.  (Make sure the messages
       printed by e2fsck are in English; if your system has been configured so
       that  e2fsck’s  messages  have  been  translated into another language,
       please set the the  LC_ALL  environment  variable  to  C  so  that  the
       transcript  of  e2fsck’s  output  will be useful to me.)  If you have a
       writable 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).   The
       most useful data you can send to help reproduce the bug is a compressed
       raw image dump of the filesystem, generated using e2image(8).  See  the
       e2image(8) man page for more details.

       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 <tytso@mit.edu>.

SEE ALSO

       badblocks(8),   dumpe2fs(8),   debugfs(8),    e2image(8),    mke2fs(8),
       tune2fs(8)