HP 9000 Virtual Library System - Manual (Page 49)

5 Automigration/Replication
Instead of the preferred method of copying virtual media to physical media via the backup
application, another option is to perform transparent tape migration via the VLS device using
automigration. Automigration describes the feature in which the Virtual Library System acts as a
tape copy engine that transfers data from virtual cartridges on disk to a physical tape library
connected to the VLS device. The VLS automigration feature uses Echo copy, which automatically
synchronizes the physical cartridges to matching virtual cartridges (with the same barcodes) based
on user-defined policies and is totally transparent to the backup application.
You can also copy virtual media using replication. Replication provides automigration from the
source VLS across the LAN/WAN to a remote virtual destination library. See
Replication
Concepts (page 50) .
This section describes automigration topics from overall automigration concepts to specific operations
you can perform on your system.
NOTE: Throughout the automigration windows, a SAN library refers to a destination library that
is connected to the source library through the SAN and uses the automigration feature. A LAN/WAN
library refers to a remote destination library that is connected to the source through the LAN/WAN
and uses the replication feature.
NOTE: When a list of slots is displayed, the message, “[#] items found, displaying 1 to 20.”
appears. If there are more than 20 items found, scroll through them using the arrows pointing right
and left at the far right-hand side at the top of the list. Also, in some cases, only available slots or
only slots containing tapes appear in the list.
NOTE: For each procedure described in this chapter, at least one means of access to the relevant
screen or menu is specified. However, links are often provided in the main window that can be
used as a shortcut to other windows or menus.
Understanding Automigration Concepts
Before using automigration, review the information in this section. This will allow you to create
copy pools and automigration policies appropriate to meet your storage needs.
Echo Copy Concepts
Echo copy acts as a transparent disk cache to the physical library, so that the backup application
writes to virtual cartridges in the virtual library. Automigration then automatically schedules the
copies from virtual cartridges to physical cartridges with matching barcodes, based on the
automigration policies the user establishes.
Echo copy is managed through the automigration software, not the backup application. For that
reason:
•
The destination library is not visible to the backup application, so it does not need licensing.
•
Copy traffic is no longer routed through the SAN.
•
All destination tapes created by echo copy are in the native tape format, so they can be
restored directly from any tape drive or library that is visible to the backup application.
When determining whether to use echo copy pools, remember:
•
The backup application will not be aware of any copy failures.
•
Any mistakes in destination library media management will also affect the virtual cartridges.
For example, if new tapes are not loaded into the destination library, the physical copy will
not exist.
Understanding Automigration Concepts 49