IBM Tivoli Storage FlashCopy Manager for VMware, Version 4.1

SAN Volume Controller and Storwize V7000 features

SAN Volume Controller 5.1 (or later) and Storwize V7000 provide a cascade feature that can be used with Tivoli® Storage FlashCopy® Manager for VMware.

These storage systems provide a FlashCopy cascading feature that can restore FlashCopy backups before completion of a background copy. This feature allows the target volume in one mapping to become the source volume in another mapping. You must use space-efficient volumes as backup targets because the background copy rate must be set to zero to prevent the FlashCopy target from becoming fully allocated.

The following list summarizes information that you must know before you use the cascading feature of SAN Volume Controller 5.1 (or later) and Storwize V7000 with Tivoli Storage FlashCopy Manager for VMware operations:

Physical capacity

The physically allocated capacity of a space-efficient target volume must contain sufficient space. It must be large enough to contain all changes that occur to your production environment between the current and the subsequent backup. If it is not large enough, the target volume goes offline and the corresponding backup becomes invalid.

Tip: You can use the SAN Volume Controller and Storwize V7000 AUTOEXPAND option to create “auto-expandable” target volumes. In this case, extra storage is assigned to the target whenever storage capacity decreases and sufficient extra capacity is available.

Target sets

Tivoli Storage FlashCopy Manager for VMware cannot reuse a target set as the source for a new FlashCopy backup unless it corresponds to the last FlashCopy mapping in a cascaded FlashCopy relation. This situation implies that whenever Tivoli Storage FlashCopy Manager for VMware reuses a target set, it deletes all backups that are created before this point in time. This situation occurs when the following settings exist:

The same profile for your Tivoli Storage FlashCopy Manager for VMware backups is used.
This profile contains only one DEVICE_CLASS statement.

Tivoli Storage FlashCopy Manager for VMware issues a warning that the target set is not available. This warning is issued when a target volume in one mapping is a source volume in another mapping but is not the last mapping in the cascade.

Recommendations

Recommendations for SAN Volume Controller 5.1 or later, and Storwize V7000 environments:

Do not use space-efficient volumes as source volumes.
Decide whether you want to use space-efficient or fully allocated backup targets.

Complete parameter descriptions are available in Tivoli Storage FlashCopy Manager for VMware configuration files.

Examples

The following extract shows a sample profile with two different device classes. One is used for Tivoli Storage FlashCopy Manager for VMware only and the other is used for Tivoli Storage FlashCopy Manager for VMware backups that are offloaded to tape by using Tivoli Storage Manager for Virtual Environments. The device classes that are used in the different backup runs can be configured in the backup wizard of the Tivoli Storage FlashCopy Manager for VMware GUI.

>>> DEVICE_CLASS DISK_ONLY
 COPYSERVICES_HARDWARE_TYPE SVC
FLASHCOPY_TYPE NOCOPY # space efficient targets
TARGET_SETS 1 2 3
TARGET_NAMING %SOURCE_%TARGETSET
...
 <<<
>>> DEVICE_CLASS DISK_TSM
COPYSERVICES_HARDWARE_TYPE SVC
FLASHCOPY_TYPE NOCOPY # space efficient targets
TARGET_SETS DUAL
TARGET_NAMING %SOURCE_%TARGETSET
...
<<<

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