Deleting snapshot data or snapshot xp pairs – HP StorageWorks XP Remote Web Console Software User Manual
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To restore a Snapshot XP pair, use a RAID Manager command. For more information, see ”
Copy Threshold option: If the local disk array’s load increases, host server I/O performance (response)
might be degraded. If Snapshot XP performs restore operations when the disk array’s load is heavy, it is
more likely that host server I/O performance (response) might be degraded. The Copy Threshold option
temporarily stops copy processing caused by restore operations when the disk array’s load is heavy. If you
enable this option, you can minimize the degradation of host I/O performance by temporarily stopping
copy processing caused by restore operations when the disk array’s load is heavy.
The Copy Threshold option is effective only when the disk array’s load is heavy. When the Copy Threshold
option is in effect, all copy processing by restore operations stop. For more information about setting the
Copy Threshold option, contact your HP Account Support Representative.
NOTE:
Copy operations stopped by the Copy Threshold option resume when the disk array’s load
become light. If this option is in effect, copy operations for Snapshot XP and the following software
products stop when the disk array’s load is heavy:
•
Business Copy XP
•
ShadowImage for z/OS®
•
Hitachi FlashCopy Mirroring
•
Hitachi FlashCopy Mirroring Version 2
•
Flex Copy XP
•
Auto LUN XP
Deleting snapshot data or Snapshot XP pairs
The status of the Snapshot XP pair is PSUE (status when failure occurred) when, as a result of writing data
in that pair’s volume, the snapshot data’s capacity exceeds the pool’s capacity specified when the pool
was created. You cannot create new Snapshot XP pairs and snapshot data cannot be stored in the pool.
Therefore, you must delete unnecessary snapshot data. There are two ways to delete snapshot data. One
way is to delete the Snapshot XP pair itself. The other way is to delete only the snapshot data.
When you delete the Snapshot XP pair itself, snapshot data stored in the pool is deleted and the
relationship between the P-VOL and S-VOL is released. On the other hand, if you delete only snapshot
data, the relationship between the P-VOL and S-VOL is maintained. When you delete only snapshot data,
the snapshot ID of the deleted snapshot data can be assigned to the newly stored snapshot data of the
Snapshot XP pair.
To delete snapshot data or Snapshot XP pairs, use a RAID Manager command. When deleting Snapshot
XP pairs, you can also use the Pairsplit -S pane in Command View XP or XP Remote Web Console. For
more information, see ”
NOTE:
•
After issuing the command to delete snapshot data, no more snapshot data for that Snapshot XP pair is
stored in the pool, even if the host tries to write data in the P-VOL. To store snapshot data for that
Snapshot XP pair again, you must issue the command for storing snapshot data.
•
The required time for deleting snapshot data or Snapshot XP pairs is several seconds, and sometimes
more than 10 minutes. The time increases if the deleted pair uses a large amount of the pool or if
multiple pairs are deleted at one time.
•
The more disk adaptors that are used in the disk array, the shorter the time required for deleting
snapshot data or Snapshot XP pairs. Since the XP1000 has a smaller number of disk adaptors than the
XP12000, the XP10000 needs a longer time to delete snapshot data or Snapshot XP pairs than the
XP12000, even if the operational conditions are the same.
•
When you delete a Snapshot XP pair, the volumes’ status becomes SMPL(PD). Use the Business Copy
XP main pane to see the volume’s status. Using RAID Manager, you can check the volume status with
the
pairdisplay
command, but you cannot distinguish between SMPL and SMPL(PD) volumes. To