e2fsck (8)


       e2fsck - check a Linux second extended file system


       e2fsck  [ -pacnyrdfvstDFSV ] [ -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 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.


       -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 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.

              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

       -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:

                          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.

       -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

       -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.)
              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).

E2fsprogs version 1.32           November 2002                       e2fsck(8)