fsck, fsck1 - perform file system consistency check

     fsck [-aclmrs] [device] ...


     -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


     fsck /dev/hd4       # Check file system on /dev/hd4

     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/hd3
                         # Check and list /dev/hd3 i-nodes 2 & 3


     Fsck performs consistency checks on the file systems which reside on  the
     specified  devices.  Fsck1 is an alternate version 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 buffered 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.

     mkfs(1), mount(1).