NAME

     fsck, fsck1 - perform file system consistency check


SYNOPSIS

     fsck [-aclmrs] [device] ...


OPTIONS

     -a   Automatically repair inconsistencies

     -c   Check and list only the specified i-nodes

     -l   List the files and directories in the filesytem

     -r   Prompt user for repairs if inconsistencies are found

     -s   List the superblock of the file system


EXAMPLES

     fsck /dev/c0d0p3    # Check file system on /dev/c0d0p3

     fsck -a /dev/at0    # Automatically fix errors on /dev/at0

     fsck -l /dev/fd0    # List the contents of /dev/fd0

     fsck -c 2 3 /dev/c0d0p2
                         # Check and list /dev/c0d0p2 i-nodes 2 &
                         3


DESCRIPTION

     Fsck performs consistency checks on the file  systems  which
     reside on the specified devices.  Fsck1 is an alternate ver-
     sion for use on obsolete V1 file systems.  When  either  the
     -a  or  -r flags are given, the file system will be repaired
     if errors are found.  Before running fsck on a mounted  file
     system,  it  must  first  be  unmounted.  Trying to repair a
     mounted  file  system  is  dangerous  and  should   not   be
     attempted.

     To repair the root file system (which cannot be  unmounted),
     first  type  CTRL-F9  at  the  console  to  kill any and all
     processes.  Log back in as root, type sync to force any buf-
     fered  changes to disk, run fsck on the root file system and
     immediately reboot the computer by typing reboot.

     It is necessary to kill all processes before  repairing  the
     root  file  system  to  prevent them from modifying any disk
     blocks while fsck is running.  This is  only  necessary  for
     the  root  file  system, any other file system can simply be
     unmounted before it is checked.


SEE ALSO

     mkfs(1), mount(1).