fsck.gfs2(8)						      System Manager's Manual						      fsck.gfs2(8)

NAME

       fsck.gfs2 - Offline GFS and GFS2 file system checker

SYNOPSIS

       fsck.gfs2 [OPTION]... DEVICE

WARNING

       All  computers  must  have  the	filesystem unmounted before running fsck.gfs2.	Failure to unmount from all nodes in a cluster will likely
       result in filesystem corruption.

DESCRIPTION

       fsck.gfs2 will check that the GFS or GFS2 file system on a device is structurally valid.  It should not be run on a  mounted  file  system.
       If file system corruption is detected, it will attempt to repair the file system.  There is a limit to what fsck.gfs2 can do.  If important
       file system structures are destroyed, such that the checker cannot determine what the repairs should be, reparations could fail.

       GFS2 is a journaled file system, and as such should be able to repair damage to the file system on its own.  However, faulty  hardware  has
       the  ability  to  write	incomplete  blocks to a file system thereby causing corruption that GFS2 cannot fix.  The first step to ensuring a
       healthy file system is the selection of reliable hardware (i.e. storage systems that will write complete blocks -  even	in  the  event	of
       power failure).

       Note:  Most file system checkers will not check the file system if it is "clean" (i.e. unmounted since the last use).  The fsck.gfs program
       behaves differently because the storage may be shared among several nodes in a cluster, and therefore problems may have been introduced	on
       a  different  computer.	Therefore, fsck.gfs2 will always check the file system unless the -p (preen) option is used, in which case it fol-
       lows special rules (see below).

OPTIONS

       -a     Same as the -p (preen) option.

       -f     Force checking even if the file system seems clean.

       -h     Help.

	      This prints out the proper command line usage syntax.

       -q     Quiet.

       -n     No to all questions.

	      By specifying this option, fsck.gfs2 will only show the changes that would be made, but not make any changes to the filesystem.

       -p     Preen (same as -a: automatically repair the file system if it is dirty, and safe to do so, otherwise exit.)

	      Note: If the file system has locking protocol lock_nolock, the file system is considered a non-shared storage device and the fsck is
	      deemed  safe.   However,	fsck.gfs2  does  not know whether it was called automatically from the init process, due to options in the
	      /etc/fstab file.	Therefore, if the locking protocol is lock_dlm and -a or -p was specified, fsck.gfs2 cannot determine whether  the
	      disk  is	mounted by other nodes in the cluster.	Therefore, the fsck is deemed to be unsafe and a warning is given if any damage or
	      dirty journals are found.  In that case, the file system should be unmounted from all nodes in the cluster and fsck.gfs2	should	be
	      run manually without the -a or -p options.

       -V     Version.

	      Print out the program version information.

       -v     Verbose operation.

	      Print more information while running.

       -y     Yes to all questions.

	      By specifying this option, fsck.gfs2 will not prompt before making changes.

																      fsck.gfs2(8)