\- migrate files between Lustre OSTs
.SH SYNOPSIS
.B lfs_migrate
-.RB [ --dry-run ]
-.RB [ --help|-h ]
+.RB [ "-A " [ -C \fI<cap> \fR] [ -M \fI<min_free> \fR] [ -X \fI<max_free> \fR]]
+.RB [ --dry-run | -n ]
+.RB [ --help | -h ]
.RB [ --no-rsync | --rsync ]
-.RB [ --quiet|-q ]
-.RB [ --restripe|-R ]
-.RB [ --skip|-s ]
-.RB [ --verbose|-v ]
-.RB [ --yes|-y ]
+.RB [ --pool | -p \fI<pool> \fR]
+.RB [ --quiet | -q ]
+.RB [ --restripe | -R ]
+.RB [ --stripe-count | -c \fI<stripe_count> \fR]
+.RB [ --stripe-size | -S \fI<stripe_size> \fR]
+.RB [ --skip | -s ]
+.RB [ --verbose | -v ]
+.RB [ --yes | -y ]
+.RB [ -D ]
.RB [ -0 ]
-.RI [ FILE | DIR ]...
+.RI [ FILE | DIR ] ...
.br
.SH DESCRIPTION
.B lfs_migrate
script to indicate a dry-run (no modifications made), and is not passed to
.B lfs migrate
as the non-block option. To specify non-block, use the long option
-.IR --non-block .
+.BR --non-block .
.PP
The current file allocation policies on MDS dictate where the new files
are placed, taking into account whether specific OSTs have been disabled
or OST index of a new file).
.SH OPTIONS
.TP
-.B \\--dry-run
+.B \\--dry-run|-n
Only print the names of files to be migrated.
.TP
+.B \\-D
+Do not use direct I/O to copy file contents.
+.TP
+.B \\-A
+Automatically determine the stripe count for the file, using the algorithm
+count = sqrt(filesize_in_GB) + 1. This option may not be specified at the
+same time as the \fB-c \fRor \\-R \fRoptions.
+.TP
+.B \\--stripe-count|-c \fI<stripe_count>
+Restripe file using the specified \fIstripe_count\fR. This option may not be
+specified at the same time as the \fB-A \fRor \fB-R \fRoptions.
+.TP
+.B \\-C \fI<cap>
+When \fB-A \fRis set, limit the migrated file to use on each OST at most
+1/\fIcap \fRof the available space of the smallest OST. If this option is not
+set, a default value of 100 is used, limiting the object size to 1% of available
+space.
+.TP
.B \\--help|-h
-Display help information.
+Display usage message.
.TP
.B \\--no-rsync
Do not fall back to using rsync if
-.BR lfs (1) " migrate" " fails."
-Cannot be used at the same time as \fI--rsync\fR.
+.BR lfs-migrate (1) " fails."
+Cannot be used at the same time as \fB--rsync\fR.
+.TP
+.B \\--min-free|-M \fI<min_free>
+When \fB-A \fRis set, only consider OSTs with free space greater than the
+\fImin_free \fRvalue to be available for migration. The value is specified in
+KB. If this option is not set, a default of 256MB is used.
.TP
-.B \\--quiet|-q
+.BR \\--pool | -q \fI<pool>
+Migrate files to specified pool.
+.TP
+.BR \\--quiet | -q
Run quietly (don't print filenames or status).
.TP
.B \\--rsync
Force rsync to be used instead of
-.BR lfs (1) " migrate" .
-May not be used at the same time as \fI--no-rsync\fR.
+.BR lfs-migrate (1) .
+May not be used at the same time as
+.BR --no-rsync .
.TP
.B \\--restripe|-R
Restripe file using default directory striping instead of keeping striping.
-This option may not be specified at the same time as the -c or -S options
-(these options are passed through to
+This option may not be specified at the same time as the \fB-A\fR, \fB-c\fR, or
+\fB-S \fRoptions. (these options are passed through to
.BR "lfs migrate" ,
and are therefore not listed here).
.TP
Skip file data comparison after migrate. Default is to compare migrated file
against original to verify correctness.
.TP
+.B \\--stripe-size|-S
+.I <stripe_size>
+Restripe file using the specified stripe size. This option may not be
+specified at the same time as the \fB-R \fRoption.
+.TP
.B \\--verbose|-v
Show verbose debug messages.
.TP
+.B \\--max-free|-X \fI<max_free>
+When \fB-A \fRis set, \fImax_free \fRis the maximum amount of free space that
+can be considered available for the migration of the file on each OST. The
+value is specified in KB. This option is useful for testing, by simulating
+OSTs that are nearly full.
+.TP
.B \\--yes|-y
Answer 'y' to usage warning without prompting (for scripts, use with caution).
.TP
Input file names on stdin are separated by a null character.
.SH EXAMPLES
To rebalance all files within
-.I /testfs/jobs/2011
-(which are known not to be modified by in-use programs):
+.IR /testfs/jobs/2011 :
.IP
lfs_migrate /testfs/jobs/2011
.PP
To migrate files within the
.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) after
-disabling file creation on testfs-OST0004 (this is needed on all MDS nodes):
+larger than 4GB (because it is more efficient to migrate a few large files than
+many small ones), and older than two days (to avoid files that are in use) to
+use auto-restriping for these files, after disabling file creation on
+testfs-OST0004 (this is needed on all MDS nodes):
.IP
+.nf
mds# lctl set_param osp.testfs-OST0004*.max_create_count=0
-client# lfs find /testfs -obd testfs-OST0004 -size +4G -mtime +2d | lfs_migrate -y
+client# lfs find /testfs -obd testfs-OST0004 -size +4G -mtime +2d | lfs_migrate -y -A
mds# lctl set_param osp.testfs-OST0004*.max_create_count=20000
+.fi
+.PP
+To use automatic restriping, and limit the object size per OST to 5% of
+current free space:
+.IP
+lfs_migrate -A -C 20 /testfs/jobs/2011
.SH NOTES
In versions prior to 2.5,
.B lfs_migrate
will be lost.
.SH AVAILABILITY
.B lfs_migrate
-is part of the
-.BR Lustre (7)
+is part of the
+.BR Lustre (7)
filesystem package. Added in the 1.8.4 release.
.SH SEE ALSO
.BR lfs (1)
git://git.whamcloud.com / fs / lustre-release.git / blobdiff