Multiple Virtual Libraries - HP StorageWorks 12000 - Virtual Library System EVA Gateway Manual

Figure 63 Multiple Virtual Libraries
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In this use case, the physical tape library slots are split into separate slot ranges, with each slot range
being assigned to a different virtual library. This allows separate backup servers to backup to their
own dedicated virtual libraries. During the echo copy window, all the virtual cartridges from the virtual
libraries are automatically and transparently copied to the single physical tape library. This scheme
provides daily off-site protection and archiving of the physical tapes.
The user can configure additional virtual slots in the virtual libraries. That is, there can be more virtual
slots than the number of physical slots mapped to the virtual library, to provide spare slots for restore
from disk. These additional slots in the virtual library can also be used to contain purely virtual media
(for example, media that has no mapping to any physical tape). The user can then create a separate
media pool for the purely virtual cartridges, so that not all backups go to physical tape. For example,
the user can direct full backups to the media pool containing the automigration virtual cartridges, and
incremental backups to the purely virtual media. Thus, only full backups are going to physical tape.
An alternative to this would be to create a separate virtual library for incremental backups which
would contain purely virtual cartridges.
Backup to a Shared Virtual Library
In this use case, the customer has multiple backup hosts on the SAN fabric that are sharing a single
virtual library on the VLS device. This is the normal configuration for the majority of enterprise customers.
Even though this shared library configuration allows tape copying via the backup application, some
customers still wish to use automigration to reduce the licensing costs of the backup application or
remove copy data from their SAN. See Figure 64.
146 Virtual Library Systems