# fsck(1)

## 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/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

## DESCRIPTION

         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.

## SEE ALSO

         mkfs(1), mount(1).