Zero downtime backup and HP StorageWorks Continuous Access EVA

Data Protector A.05.10 - ZDB for EVA in the CA Configuration
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Chapter 2: Overview
Until now, Data Protector enabled ZDB to be performed only on EVA+BC. On such an EVA, you can choose to perform any of the
three snapshot backup session types: ZDB disk backup, ZDB disk/tape backup, and ZDB tape backup. If you back up the data using
either of the first two backup session types, you can later restore it using instant recovery (IR).
2.1 ZDB Tape Backup on CA EVA
When Data Protector is upgraded with the ZDB for CA EVA extension, ZDB functionality is also enabled for the destination virtual
disks on CA EVA. However, on such an EVA configuration IR is not possible, and - consequently - only ZDB tape backup sessions can
be performed. The data backed up in ZDB tape backup session can be restored using the standard Data Protector restore procedure.
Nevertheless, the ZDB for CA EVA extension enables you to configure the ZDB tape backup specification in such a way that after the
backup to tape media, the replica is kept on the EVA disk array for purposes other than IR.
The ZDB for CA EVA extension was designed to meet the requirements of the following Data Protector customer groups:
• The customers who are using the CA EVA high availability solution with one of the EVA disk arrays not fully loaded. This EVA
disk array can be utilized to create snapshots and back up data to the tape device. During the ZDB process, the performance of the
other EVA disk array is not affected.
• The customers who are using the CA EVA high availability solution, and who want to have backups present on both locations.
This extra backup policy increases the safety of the backed up data.
For conceptual overview of the CA EVA operation in a Data Protector backup environment and the physical layout of the EVA disk
arrays in the Data Protector cell, see Chapter 3, “Concepts,” on page 9. For more information on EVA disk arrays, refer to the Virtual
array systems section of the web page http://h18004.www1.hp.com/storage/arraysystems.html
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2.2 Upgrade Considerations
Note that after upgrading your EVA+BC high-availability environment to CA EVA, and upgrading Data Protector with the ZDB for
CA EVA extension, IR will only be enabled for those virtual disks that are not part of a copy set (are configured as a local storage
only). This means that for the virtual disks that are part of a copy set:
• The data that was backed up on EVA+BC in a ZDB disk backup session cannot be restored, as IR is the only method that can be
used for restoring such data.
• The data that was backed up on EVA+BC in a ZDB disk/tape backup session can be restored only from tape media.
• The data that was backed up on EVA+BC in a ZDB tape backup session can be restored as usual.
The above IR limitation is imposed by the CA EVA configuration, and not by the ZDB for CA EVA extension.