HP XP7 Storage - Manual (Page 139)

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When a THP V-VOL is used for a Cnt Ac-J Z P-VOL or S-VOL, the Cnt Ac-J Z of the allocated
pages for the THP V-VOL is included in the Cnt Ac-J Z licensed capacity. If the actual licensed
capacity exceeds the available licensed capacity, you may use Cnt Ac-J Z for 30 days. After
30 days, Cnt Ac-J Z pairs may only be split or released.
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When specifying a THP V-VOL that has allocated pages to a Cnt Ac-J Z S-VOL, be aware that
used pool capacity will become temporarily larger than the actual capacity, because pages
must be reallocated in the THP V-VOL. Therefore, before creating the pair:
◦ Make sure that THP V-VOL pool capacity is sufficient.
◦ Make sure that the pool-VOLs, which are added to a pool, are not blocked. If the
pool-VOLs are blocked, restore the volume status and then create the pair.
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You can use THP V-VOLs that are also used by Business Copy Z or that are in a Auto LUN
migration plan. To do so, proceed as follows:
1.
Delete the Business Copy Z pair or disable the Auto LUN setting.
2. Create the Cnt Ac-J Z pair.
3. Re-create the Business Copy Z pair or the Auto LUN migration plan.
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Be aware that when a THP V-VOL is used as the Cnt Ac-J Z S-VOL, you might not be able to
update the Cnt Ac-J Z S-VOL because the capacity of the pool-VOL is full. In this instance, pair
status changes to Suspend.
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You can reclaim zero pages of the THP V-VOL to release the appropriate pages. Free pool
capacity increases after zero pages are reclaimed, but pages to which the control cylinders
are assigned cannot be released. Therefore, when the pair is created using THP V-VOLs only,
page capacity or P-VOL and S-VOL license capacity might be different in the following cases:
◦ If the page in track is allocated to the P-VOL, Cnt Ac-J Z overwrites the data by copying
it to the S-VOL, even if the track has no records. The new page to which the control
cylinders are assigned might be allocated because control cylinder information controlling
the track is updated when the S-VOL data is overwritten.
In this case, pages to which the control cylinders are assigned cannot be released.
Therefore, there might be more pages allocated to the S-VOL than to the P-VOL.
◦ When P-VOL zero data pages are copied to the S-VOL, new pages might not be allocated
to S-VOL.
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When S-VOL data is updated while the pair is suspended, new pages to which the control
cylinders are assigned might be allocated. In this case, pages to which the control cylinders
are assigned cannot be released even after the pair is resumed. Therefore, there might
be more pages allocated to the S-VOL than to the P-VOL.
Resource Partition
You can specify Resource Partition volumes as Cnt Ac-J Z P-VOL and S-VOL as long as they belong
to the same resource group. For journal volumes, use a Res Par OPEN-V virtual volume.
For more information, see HP XP7 Provisioning for Mainframe Systems User Guide
External Storage
You can create Cnt Ac-J Z pairs using External Storage-configured external volumes.
For more information, see the HP XP7 External Storage for Open and Mainframe Systems User
Guide.
Virtual LVI
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Continuous Access Journal Z supports the Virtual LVI feature, which allows you to configure
custom-size LDEVs that are smaller than standard-size LDEVs. When custom-size LDEVs are
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