LU-6475 mdt: race between open and migrate

[fs/lustre-release.git] / lustre / doc / lfs_migrate.1

diff --git a/lustre/doc/lfs_migrate.1 b/lustre/doc/lfs_migrate.1
index a1bf7e6..c6f198a 100644 (file)
--- a/lustre/doc/lfs_migrate.1
+++ b/lustre/doc/lfs_migrate.1
@@ -27,7 +27,7 @@ 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
@@ -88,15 +88,20 @@ against original to verify correctness.
 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/dir
+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" .
@@ -105,8 +110,6 @@ Eventually, this functionality will be integrated into
 .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