Replication Concepts - HP 12000 User Manual

the backup application using SMI-S V1.3 software, and the VLS then performs the specified copy
(for example from a virtual cartridge to a destination cartridge, or from a destination cartridge
back to a virtual cartridge, etc.). The backup application tracks the virtual cartridges and the
destination cartridges separately since they have different barcodes and potentially different
contents.
NOTE: When smart copy jobs are triggered, they can override (reschedule) lower priority jobs,
such as echo copy jobs, up to the maximum number of tape drives allocated to their smart copy
pool. If you configure both smart copy pools and echo copy pools on the same VLS, it is advised
that some destination library tape drives remain unallocated to smart copy pools so that echo copy
operations can still continue while smart copy is active.

Replication Concepts

Replication provides automigration via LAN/WAN between two VLS devices. Because replication
is a feature of automigration and uses the same Echo Copy policies that allow flexible cartridge/slot
based configuration, any number of different replication configurations can be supported. You
establish a replication policy and echo copy pools using Command View VLS in the same way
you set up automigration with a destination library on the SAN.
NOTE: The replication feature cannot use smart copy, only echo copy.
During replication, the source VLS copies data to the echo copy pools on a replication library that
is on the source. During the user-defined availability window, this replication library migrates data
to the destination library, known as the LAN/WAN replication target.
The following are two of many possible replication configurations:
Data center to data center
Designate one VLS as the source and a second VLS as the destination. Configure the destination
VLS to present a LAN/WAN replication target that is visible to the source VLS. The source
VLS performs normal backups during the regular backup window, and during the availability
window the source virtual cartridges automatically migrate to matching virtual cartridges on
the destination VLS. The same configuration is also used in the other direction so there is a
backup library and a LAN/WAN replication target library on both devices.
Branch office to a main data center
Divide a single destination target into multiple slot ranges to allow a many-to-one configuration
without needing a separate replication library for each branch office. In this way, the VLS
replication can scale to hundreds of branch offices all replicating to a single large device.
Replication can be configured to operate in one of two modes:
Deduplication-enabled replication — the virtual cartridge on the source VLS is deduplicated
against the virtual cartridge on the target VLS. In this manner, only data that has changed is
transmitted over the network to the target VLS. This mode requires that deduplication is licensed
and enabled on both the source and the target VLS.
Whole cartridge replication — the entire virtual cartridge is copied from the source VLS to the
target VLS.
Understanding Automigration Concepts 35