HP StorageWorks XP Remote Web Console Software - Manual (Page 15)

Snapshot XP user guide 15
information about shared memory requirements, see Table 4 on page 18. To install additional shared
memory, contact your HP Account Support Representative.
There are two areas in the V-VOL management area: pool management block and pool association
information. When you create pools or Snapshot XP pairs, the pool management block or pool association
information is stored in the V-VOL management area. Therefore, the V-VOL management area’s available
capacity decreases. When all of the V-VOL management area’s capacity is used, the capacity ratio of the
pool management block and pool association information in the V-VOL management area is fixed. If the
pool management block’s capacity is insufficient, problems might occur. For example, you cannot create
pools or pools with a large capacity. To solve such problems, initialize the V-VOL management area. For
more information, see ” Initializing V-VOL management areas or pool management blocks ” on page 39.
Creating pools
A pool is an area where the snapshot data that Snapshot XP obtains is stored. A pool consists of multiple
pool-VOLs, and snapshot data is stored in a pool-VOL. You can register 1,024 pool-VOLs in a pool. You
can create 128 pools in a disk array. Figure 2 illustrates the relationship between Snapshot XP pairs and
pools.
Figure 2 Snapshot XP pair and pool mechanism
You must create a pool when you use Snapshot XP. Pool-VOLs registered in a pool can be added, but
cannot be deleted during the operation. In addition, to delete the pool itself, you must delete all snapshot
data in the pool.
CAUTION: A pool’s capacity equals the total capacity of the pool-VOLs registered in the pool. The status
of the Snapshot XP pair is PSUE (status when failure occurred) when the pool’s usage rate exceeds the
pool’s capacity as a result of writing data in that pair’s volume. Snapshot data cannot be stored in the
pool, and new Snapshot XP pairs cannot be created. For more information about ensuring sufficient pool
capacity, see ” Notes on creating pools ” on page 24.
To create a pool, use the Pool pane in Command View XP or XP Remote Web Console. For more
information, see ” Creating or deleting pools ” on page 34.
Creating virtual volumes
A V-VOL is a virtual volume defined in a VDEV. You must create a V-VOL before you create a Snapshot XP
pair because you must use a V-VOL as the Snapshot XP pair’s S-VOL.