HP StorageWorks XP Remote Web Console Software - Manual (Page 17)

Snapshot XP user guide 17
can create 128 pools in an 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 using Snapshot XP. You can add pool-VOLs registered in a pool, but cannot
delete pool-VOLs 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
Snapshot XP pair’s status 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. You cannot store Snapshot data in the
pool, and you cannot create Snapshot XP pairs. For more information about ensuring sufficient pool
capacity, see ” Notes on creating pools ” on page 28.
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 43.
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.
A V-VOL’s definition cannot be released if the V-VOL is being used as a Snapshot XP pair’s S-VOL. To
release the definition, delete the Snapshot XP pair using the V-VOL.
CAUTION: If you are using HP-UX® as a host server, observe the following when executing the
command on V-VOLs to recognize the device from the host server:
• If the host server already recognizes the device, do not change its volumes to V-VOLs.
• Before executing the command to recognize the device, create Snapshot XP pairs and store snapshot
data.
If you do not follow these cautions, an error might occur and the host server might be terminated. If the
host server is terminated because of the command to recognize the device, retry the command using the
following steps:
1. Force the command process and its parent process to terminate.