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
       follows special rules (see below).

       fsck.gfs2 will log to the system log on start and exit to aid debugging and administration.

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)