.TH "defragfs.ocfs2" "8" "January 2012" "Version @VERSION@" "OCFS2 Manual Pages"
.SH NAME
defragfs.ocfs2 \- online defragmenter for ocfs2 filesystem
.SH SYNOPSIS
defragfs.ocfs2 [\-c] [\-v] [\-l] [\-g] [\-h][target]...
.SH DESCRIPTION
.PP
.B defragfs.ocfs2
reduces fragmentation of ocfs2 based file. The file targeted by
.B defragfs.ocfs2
is created on ocfs2 filesystem The targeted file gets more contiguous blocks and improves the file access
speed.
.PP
.I target
is a regular file, a directory, or a device that is mounted as ocfs2 filesystem.
If
.I target
is a directory,
.B defragfs.ocfs2
reduces fragmentation of all files in it. If
.I target
is a device,
.B defragfs.ocfs2
gets the mount point of it and reduces fragmentation of all files in this mount
point.
.SH OPTIONS
.TP
.B \-c
Print the numbers of files that should be processed 
.TP
.B \-v
verbose mode, the current fragmentation count and the ideal fragmentation count are
printed for each file.
.IP
If this option is specified,
.I target
is never defragmented.
.TP
.B \-l
.B defragfs.ocfs2 
will run in low io mode, which means it will regularly yield cpu to allow other processes to run.
.TP
.B \-g
.B defragfs.ocfs2
regularly records the current progress. So if it is interrupted, the next time you run 
.B defragfs.ocfs2
with this option, it will resume from the recorded progress. 
Note that if this option is specified, other options are ignored and replaced by those that were recorded.
.TP
.B \-h
Print help info

.SH NOTES
.B defragfs.ocfs2
does not support files in lost+found directory. When
.I target
is a device or a mount point,
.B defragfs.ocfs2
doesn't defragment files in mount point of other device.
.PP
It is completely
.B not
recommended to run against a file while it is actively in another application.
Since the read/write of a file involves a dlm lock, this can result in a performance slowdown to both defragfs.ocfs2
and the application due to contention.
.PP
If the file system's free space is fragmented, or if there is
insufficient free space available, defragfs.ocfs2 may not be able
to improve the file's fragmentation.
.PP
Non-privileged users can execute
.B defragfs.ocfs2
to their own file. Therefore, it is desirable to be executed by root user.
.SH AUTHOR
Written by Larry Chen <lchen@suse.com>

