Deleting snapshot data or snapshot xp pairs – HP StorageWorks XP Remote Web Console Software User Manual
Page 19
19
NOTE:
If you restore the pair when data is written in the S-VOL instead of the snapshot data, data in the
S-VOL is written back to the P-VOL.
If there are problems with the P-VOL data during a failure, you can restore the P-VOL to the normal state
when the snapshot data was stored by executing restoration.
To restore a Snapshot XP pair, use a RAID Manager command. For more information, see ”
Copy Threshold option
: If the array’s load increases, host server I/O performance (response) might be
degraded. If Snapshot XP performs restore operations when the 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 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 array’s load is heavy.
The Copy Threshold option is effective only when the array’s load is heavy. When the Copy Threshold
option is enabled, all copy processing by restore operations stops. 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 array’s load become
light. If this option is enabled, copy operations for Snapshot XP and the following software products stop
when the 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 Snapshot XP pairs and store snapshot data 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 deleting 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 deleting 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 XP 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.