HP XP7 Storage User Manual
Page 142
If you stop an operation to reclaim zero pages in mid-stream, the pages that have been released
will remain as free pool capacity.
After an operation to reclaim zero pages, Thin Provisioning Z automatically balances usage levels
among parity groups in the pool. This rebalancing is performed on parity groups related to the
pool. If you do not want automatic balancing of the usage levels of parity groups, call HP Technical
Support to change your configuration.
Thin Provisioning Z does not automatically balance the usage levels among parity groups if the
cache memory is not redundant or if the pool usage reaches up to the threshold.
If all the tracks that belong to a page assigned to a THP V-VOL have no records written, you can
reclaim the page and return it to the pool's available capacity.
In the following cases, an operation reclaim zero pages stops and THP V-VOL pages are not
released.
•
The pool-VOL accessed by the target THP V-VOL is blocked.
•
The pool associated with the target THP V-VOL is blocked while the operation to reclaim zero
pages is in progress.
•
Cache memory failure occurs the operation to reclaim zero pages is in progress.
•
The initial copy operation between Continuous Access Synchronous Z pair, Continuous Access
Journal Z, Business Copy pair is performed on the THP V-VOL in which the zero pages are
reclaimed.
Releasing pages in a THP V-VOL
The Storage Administrator (Provisioning) role is required to perform this task.
You can reclaim pages in a THP V-VOL to free pool capacity. If a page assigned to a THP V-VOL
contains no logical records, you can reclaim the page. The used capacity of the pool can then be
decreased. Before releasing pages in a THP V-VOL, see
“About releasing pages in a THP V-VOL”
).
Procedure 10 To release pages in a THP V-VOL
1.
In the Remote Web Console main window, in the Storage Systems tree, select Logical Devices.
The following is another way to select LDEVs.
1.
In the Remote Web Console main window, in the Storage Systems tree, select Pool.
The pool name appears below Pool.
2.
Select the pool associated with the THP V-VOL that has pages you want to release.
3.
Select the Virtual Volumes tab.
2.
From the table, select the THP V-VOL that has pages you want to release.
3.
Click More Actions, and then select Reclaim Zero Pages.
The Reclaim Zero Pages window opens.
You cannot release pages in a THP V-VOL when the THP V-VOL is not in a normal status or
the THP V-VOL is in the process of reclaiming zero pages.
4.
In Task Name type a unique name for this task or accept the default, and then click Apply.
If Go to tasks window for status is checked, the Tasks window opens.
After the operation to reclaim zero pages is complete, refresh the display to update the Page Status.
If the Page Status is not immediately updated, wait a while, and then refresh the display again.
NOTE:
Completed is displayed as the Page Status even when no pages can be reclaimed.
If you have started the reclaiming zero pages operation, and the storage system is powered off
the reclaiming zero pages operation will not automatically continue after the storage system restarts.
142
Configuring thin provisioning