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NAME    [Toc]    [Back]

     fsck_ext2fs - Second Extended File System consistency  check
and interactive

SYNOPSIS    [Toc]    [Back]

     fsck_ext2fs  [-b  block#] [-d] [-f] [-m mode] [-p] [-y] [-n]
filesystem ...

DESCRIPTION    [Toc]    [Back]

     fsck_ext2fs  performs  interactive  filesystem   consistency
checks and repair
     for  each  of the filesystems specified on the command line.
It is normally
 invoked from fsck(8).

     The kernel takes care that only a restricted  class  of  innocuous filesystem
  inconsistencies  can happen unless hardware or software
failures intervene.
  These are limited to the following:

     Unreferenced inodes
     Link counts in inodes too large
     Missing blocks in the free map
     Blocks in the free map also in files
     Counts in the super-block wrong

     These are  the  only  inconsistencies  that  fsck_ext2fs  in
``preen'' mode
     (with  the  -p  option) will correct; if it encounters other
 it exits with an abnormal  return  status.   For  each
corrected inconsistency
  one  or more lines will be printed identifying the
filesystem on
     which the correction will take place, and the nature of  the
     After successfully correcting a filesystem, fsck_ext2fs will
print the
     number of files on that filesystem and the  number  of  used
and free

     If  sent a QUIT signal, fsck_ext2fs will finish the filesystem checks,
     then exit with an abnormal return status.

     Without the -p option, fsck_ext2fs audits and  interactively
repairs inconsistent
 conditions for filesystems.  If the filesystem is
     the operator is prompted for concurrence before each correction is attempted.
  It should be noted that some of the corrective actions which
     are not correctable under the -p option will result in  some
loss of data.
     The  amount and severity of data lost may be determined from
the diagnostic
 output.  The default action for each consistency correction is to
     wait  for the operator to respond ``yes'' or ``no''.  If the
operator does
     not have write permission  on  the  filesystem,  fsck_ext2fs
will default to
     a -n action.

     The following flags are interpreted by fsck_ext2fs:

     -b block#
             Use  the  block specified immediately after the flag
as the super
             block for the filesystem.  Block 8193 is usually  an
alternate super

     -d      Print debugging output.

     -f      Force checking of file systems.  Normally, if a file
system is
             cleanly unmounted, the kernel  will  set  a  ``clean
flag'' in the
             file  system  superblock  and  fsck_ext2fs  will not
check the file
             system.  This option forces fsck_ext2fs to check the
file system,
             regardless of the state of the clean flag.

     -m mode
             Use  the  mode  specified in octal as the permission
bits to use
             when creating the lost+found directory  rather  than
the default
             1777.   In  particular,  systems that do not wish to
have lost files
             accessible by all users on the system should  use  a
more restrictive
 set of permissions such as 700.

     -n       Assume  a ``no'' response to all questions asked by
             except for ``CONTINUE?'', which is assumed to be affirmative; do
             not open the filesystem for writing.

     -p      Specify ``preen'' mode, described above.

     -y       Assume a ``yes'' response to all questions asked by
             this should be used with great caution as this is  a
free license
             to  continue after essentially unlimited trouble has
been encountered.

     Inconsistencies checked are as follows:

     1.   Blocks claimed by more than one inode or the free  map.
     2.    Blocks  claimed  by  an inode outside the range of the
     3.   Incorrect link counts.
     4.   Size checks:
          Directory size not a multiple of filesystem block size.
          Partially truncated file.
     5.   Bad inode format.
     6.   Blocks not accounted for anywhere.
     7.   Directory checks:
          File pointing to unallocated inode.
          Inode number out of range.
          Dot or dot-dot not the first two entries of a directory
or having
          the wrong inode number.
     8.   Super Block checks:
          More blocks for inodes than there are in  the  filesystem.
          Bad free block map format.
          Total free block and/or free inode count incorrect.

     Orphaned  files and directories (allocated but unreferenced)
are, with the
     operator's concurrence, reconnected by placing them  in  the
lost+found directory.
   The  name  assigned  is the inode number.  If the
lost+found directory
 does not exist, it is created.  If there is insufficient space
     its size is increased.

     Because  of inconsistencies between the block device and the
buffer cache,
     the raw device should always be used.

DIAGNOSTICS    [Toc]    [Back]

     The diagnostics produced by fsck_ext2fs are fully enumerated
and explained
  in  Appendix A of Fsck - The UNIX File System Check

SEE ALSO    [Toc]    [Back]

     fs(5), fstab(5), fsck(8), fsdb(8), newfs(8), reboot(8)

OpenBSD     3.6                           June      13,      1997
[ Back ]
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