Thin provisioning, External storage access manager (esam) – HP XP P9500 Storage User Manual

Page 136

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Table 10 Whether access attribute can be changed when Cnt Ac-J P-VOL status is PAIR or COPY

Change access attribute to

Change access attribute
from

S-VOL Disable

Protect

Read Only

Read/Write

Yes

No

No

-

Read/Write

Yes

Yes

-

Yes

Read Only

Yes

-

Yes

Yes

Protect

-

No

No

Yes

S-VOL Disable.

Thin Provisioning

You can create a Continuous Access Journal pair by specifying a THP V-VOL (Thin Provisioning
virtual volume).

THP V-VOLs can be used for either the Cnt Ac-J P-VOL or S-VOL, or both P-VOL and S-VOL.

THP V-VOLs cannot be used for Cnt Ac-J journal volumes.

When a THP V-VOL is used for a Cnt Ac-J P-VOL or S-VOL, the Cnt Ac-J of the allocated pages
for the THP V-VOL is included in the Cnt Ac-J licensed capacity. If the actual licensed capacity
exceeds the available licensed capacity, you may use Cnt Ac-J for 30 days. After 30 days,
Cnt Ac-J pairs may only be split or released.

When specifying a THP V-VOL that has allocated pages to a Cnt Ac-J 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.

You can use THP V-VOLs that are also used by Business Copy or that are in a Auto LUN
migration plan. To do so, proceed as follows:
1.

Delete the Business Copy pair and disable the Auto LUN setting.

2.

Create the Cnt Ac-J pair.

3.

Re-create the Business Copy pair and the Auto LUN migration plan.

Be aware that when a THP V-VOL is used as the Cnt Ac-J S-VOL, you might not be able to
update the Cnt Ac-J S-VOL because the capacity of the pool-VOL is full. In this instance:

The pair is suspended.

With RAID Manager, the Cnt Ac-J pair status changes to PFUS.

In Remote Web Console, the Cnt Ac-J pair status changes to PSUS.

External Storage Access Manager (ESAM)

You can use the ESAM S-VOL as a Cnt Ac-J P-VOL. This configuration benefits the ESAM pair if
data in the P-VOL and S-VOL become inconsistent due to a disaster. In this case, you can recover
the data from the split Cnt Ac-J S-VOL.

136

Sharing volumes

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