6.0 HP StorageWorks X9000 File Serving Software CLI Reference (TA768-96040, October 2011)

ibrix_rebalance
Redistributes files among segments to balance segment utilization and server workload, or evacuates
all files from specific segments.
Description
Rebalancing files
The X9000 Software Rebalancer redistributes files among segments in a file system to balance
segment utilization and server workload. Normally all segments are rebalanced, possibly as a
cron job, but a rebalancing can be limited to specific segments. Only segments containing files
can be rebalanced.
During rebalancing, X9000 Software calculates the average aggregate utilization of all of the
source segments, and then moves files from sources to destinations to bring each source segment
as close as possible to the calculated utilization threshold. The final per-segment usage depends
on the average file size for the target file system.
If you do not specify sources or destinations, candidate segments are sorted into sources and
destinations and then rebalanced as evenly as possible.
If you specify sources, all other candidate segments in the file system are tagged as destinations,
and vice versa if you specify destinations. Following the general rule, X9000 Software calculates
the utilization threshold from the sources and then brings the sources as close as possible to this
value by evenly distributing excess files among all the destinations. If you specified sources, the
end result is that only those segments are rebalanced, and the overflow is distributed among all
remaining candidate segments. If you specified destinations, the end result is that all segments
except the specified destinations are rebalanced, and the overflow is distributed only to the
destinations.
If you specify both sources and destinations, only the specified sources are rebalanced and the
overflow is distributed among only the specified destinations.
If there is not enough aggregate room in destination segments to hold the files to be moved, X9000
Software issues an error message and does not move any files. The more restricted the number of
destinations, the higher the likelihood of this error.
Evacuating a segment
Before retiring storage, you will need to move, or evacuate, all files from the segments on that
storage to other segments in the same file system. If segments with adequate space are not available,
you will need to use ibrix_fs to extend the file system. The evacuation operation is transparent
to users or applications accessing the file system. The amount of IO activity on the segment affects
the time required for the operation.
Synopsis
Rebalance segments:
ibrix_rebalance -r -f FSNAME [-e] [[-s SRCSEGMENTLIST] [-S SRCLVLIST]]
[[-d DESTSEGMENTLIST] [-D DESTLVLIST]] [-m INACTIVESECONDS] [-v]
The command rebalances all segments or selected segments in file system FSNAME. The file system
must be mounted before it can be rebalanced. If you do not enter source and destination segment
lists, all segments are rebalanced. If you enter source and destination segments, specified by either
segment name or logical volume name, rebalancing activity is restricted to those segments.
To evacuate a segment, include the -e option. When the rebalance operation completes, you can
remove the storage from the cluster. The segment numbers associated with the storage are not
reused.
Display a summary of rebalancing and segment evacuation tasks:
108 X9000 File Serving Software commands