.TH fsck.gfs2 8

.SH NAME
fsck.gfs2 - Offline GFS and GFS2 file system checker

.SH SYNOPSIS
.B fsck.gfs2
[\fIOPTION\fR]... \fIDEVICE\fR

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

.SH 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.
.SH OPTIONS
.TP
\fB-a\fP
Same as the \fB-p\fP (preen) option.
.TP
\fB-f\fP
Force checking even if the file system seems clean.
.TP
\fB-h\fP
Help.

This prints out the proper command line usage syntax.
.TP
\fB-q\fP
Quiet.
.TP
\fB-n\fP
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.

This option may not be used with the \fB-y\fP or \fB-p\fP/\fB-a\fP options.
.TP
\fB-p\fP
Automatically repair ("preen") the file system if it is dirty and safe to do so,
otherwise exit.

If the file system has locking protocol \fIlock_nolock\fR, it is considered a
non-shared storage device and it is considered safe.  If the locking protocol
is lock_dlm and \fB-a\fP or \fB-p\fP was specified, the check is considered unsafe as it
cannot be determined whether the device is mounted by other nodes in the cluster.
In this case a warning is given if any damage or dirty journals are found. The
file system should then be unmounted from all nodes in the cluster and
fsck.gfs2 should be run manually without the \fB-a\fP or \fB-p\fP options.

This option may not be used with the \fB-n\fP or \fB-y\fP options.
.TP
\fB-V\fP
Print out the program version information.
.TP
\fB-v\fP
Verbose operation.

Print more information while running.
.TP
\fB-y\fP
Yes to all questions. By specifying this option, fsck.gfs2 will not prompt before making
changes.

This option may not be used with the \fB-n\fP or \fB-p\fP/\fB-a\fP options.