Backup Application Interaction With Replication; Presenting The Replication Target To A Different Backup Application - HP StorageWorks 12000 - Virtual Library System EVA Gateway Manual

• Active-Active: Each site requires a 4-node/4-array VLS9000 (with deduplication) shared
between backups and replication target, one rack, and four replication LTUs.
• 2x Active-Passive: Each site requires a 2-node/2-array VLS9000 (with deduplication) for backup
and a separate 2-node/2-array VLS9000 (with deduplication) for replication target, two racks,
and two replication LTUs.
In this example, it costs less to use active-active because it adds two replication LTUs but saves the
hardware/power/footprint cost of a second rack and the cost of a second VLS connectivity kit.
However, if your backups required more than half of the maximum device performance (for ex-
ample, more than two nodes out of a maximum configuration of four nodes), you may have to
deploy two devices per site. In this case, it would be cheaper licensing (and better future device
scalability) to use 2x active-passive deployment.
NOTE:
Multi-hop replication (replicating a cartridge from device A to device B, and then replicating the
replicated cartridge from device B to device C) is not yet supported.

Backup Application Interaction with Replication

The replication in both the VLS and D2D systems is mirroring the source cartridge to its matching
target cartridge so both cartridges have the same barcode, the same tape contents, etc. Backup
applications currently cannot handle seeing two copies of the same cartridge at the same time (because
to the backup application, the cartridge is a single entity in the media database). Given this limitation,
you must hide the target virtual library from the source device's backup application:
• For VLS systems, the replication target is a subset or an entire virtual library that is presented on
front-end Fibre Channel ports, so if the source backup application is running media agents on the
target site you either need to use SAN zoning or the device's LUN mapping feature to hide this
replication target virtual library from the source device's backup application.
• For D2D systems, this is currently automatic because the replication target is hidden from all ex-
ternal host access (until it is converted into a non-replicating library in the event of a disaster re-
covery).
Figure 9 Presenting the Replication Target to a Different Backup Application
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28 Concepts