1 .TH lfs_migrate 1 "Jul 21, 2010" Lustre "utilities"
4 \- simple tool to migrate files between Lustre OSTs
7 .RB [ -c <stripe_count> ]
15 .RI [ file | "directory ..." ]
19 is a simple tool to assist migration of files between Lustre OSTs. It
20 is simply copying each specified file to a new file, verifying the file
21 contents have not changed, and then renaming the new file back to the
22 original filename. This allows balancing space usage between OSTs, moving
23 files of OSTs that are starting to show hardware problems (though are still
24 functional), or OSTs will be discontinued.
30 closely integrated with the MDS, it cannot determine whether a file
31 is currently open and/or in-use by other applications or nodes. That makes
35 for use on files that might be modified by other applications, since the
36 migrated file is only a copy of the current file, and this will result in
37 the old file becoming an open-unlinked file and any modifications to that
40 Files to be migrated can be specified as command-line arguments. If a
41 directory is specified on the command-line then all files within that
42 directory are migrated. If no files are specified on the command-line,
43 then a list of files is read from the standard input, making
47 to locate files on specific OSTs and/or matching other file attributes.
49 The current file allocation policies on MDS dictate where the new files
50 are placed, taking into account whether specific OSTs have been disabled
53 (preventing new files from being allocated there), whether
54 some OSTs are overly full (reducing the number of files placed on those
55 OSTs), or if there is a specific default file striping for the target
56 directory (potentially changing the stripe count, stripe size, OST pool,
57 or OST index of a new file).
60 .B \\-c <stripe_count>
61 Restripe file using the specified stripe count. This option may not be
62 specified at the same time as the -R option.
65 Display help information.
68 Migrate files with hard links (skip by default). Files with multiple
69 hard links will be split into multiple separate files by
71 so they are skipped by default to avoid breaking the hard links.
74 Only print the names of files to be migrated
77 Run quietly (don't print filenames or status)
80 Restripe file using default directory striping instead of keeping striping.
81 This option may not be specified at the same time as the -c option.
84 skip file data comparison after migrate. Default is to compare migrated file
85 against original to verify correctness.
88 Answer 'y' to usage warning without prompting (for scripts, use with caution).
90 To rebalance all files within
93 lfs_migrate /mnt/lustre/dir
95 To migrate files within the
97 filesystem on OST0004 larger than 4GB in size:
99 lfs find /test -obd test-OST0004 -size +4G | lfs_migrate -y
101 Hard links could be handled correctly in Lustre 2.0 by using
102 .BR lfs (1) " fid2path" .
104 Eventually, this functionality will be integrated into
106 itself and will integrate with the MDS layout locking to make it safe
107 in the presence of opened files and ongoing file IO.
109 Please report all bugs to http://bugzilla.lustre.org/
114 filesystem package. Added in the 1.8.4 release.