.TH lfs_migrate 1 "Jul 21, 2010" Lustre "utilities"
.SH NAME
-.Blfs_migrate
+.B lfs_migrate
\- simple tool to migrate files between Lustre OSTs
.SH SYNOPSIS
.B lfs_migrate
+.RB [ -c <stripe_count> ]
.RB [ -h ]
.RB [ -l ]
.RB [ -n ]
+.RB [ -q ]
.RB [ -R ]
.RB [ -s ]
.RB [ -y ]
is simply copying each specified file to a new file, verifying the file
contents have not changed, and then renaming the new file back to the
original filename. This allows balancing space usage between OSTs, moving
-files of OSTs that are starting to show hardware problems (though are still
-functional), or OSTs will be discontinued.
+files off OSTs that are starting to show hardware problems (though are still
+functional), or OSTs that will be removed from the filesystem.
.PP
Because
.B lfs_migrate
is
.B not
-closely integrated with the MDS, it cannot determine whether a file
+yet closely integrated with the MDS, it cannot determine whether a file
is currently open and/or in-use by other applications or nodes. That makes
it
.B
or OST index of a new file).
.SH OPTIONS
.TP
+.B \\-c <stripe_count>
+Restripe file using the specified stripe count. This option may not be
+specified at the same time as the -R option.
+.TP
.B \\-h
Display help information.
.TP
.TP
.B \\-R
Restripe file using default directory striping instead of keeping striping.
+This option may not be specified at the same time as the -c option.
.TP
.B \\-s
skip file data comparison after migrate. Default is to compare migrated file
Answer 'y' to usage warning without prompting (for scripts, use with caution).
.SH EXAMPLES
To rebalance all files within
-.IR /mnt/lustre/dir :
+.I /testfs/jobs/2011
+(which are known not to be modified by in-use programs):
.IP
-lfs_migrate /mnt/lustre/file
+lfs_migrate /testfs/jobs/2011
.PP
To migrate files within the
-.I /test
-filesystem on OST0004 larger than 4GB in size:
+.I /testfs
+filesystem on OST0004 (perhaps because it is much more full than other OSTs),
+larger than 4GB (because it is more efficient to just migrate large files),
+and older than two days (to avoid files that are in use, though this is NOT
+a guarantee the files are not being modified, that is workload specific):
.IP
-lfs find /test -obd test-OST0004 -size +4G | lfs_migrate -y
+lfs find /testfs -obd test-OST0004 -size +4G -mtime +2d |
+ lfs_migrate -y
.SH KNOWN BUGS
Hard links could be handled correctly in Lustre 2.0 by using
.BR lfs (1) " fid2path" .
.BR lfs (1)
itself and will integrate with the MDS layout locking to make it safe
in the presence of opened files and ongoing file IO.
-.PP
-Please report all bugs to http://bugzilla.lustre.org/
.SH AVAILABILITY
.B lfs_migrate
is part of the