Figure 2 snapshot xp pair and pool mechanism, Creating virtual volumes, 2 snapshot xp pair and pool mechanism – HP StorageWorks XP Remote Web Console Software User Manual

Page 17

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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.

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