HP Application Recovery Manager software Integration guide (March 2008)

• coordinating restore session start
• requesting the instant recovery
Backup
During the Application Recovery Manager VSS integration backup, Application
Recovery Manager does not interact directly with each writer, but through the VSS
interface. It uses the VSSBAR agent to coordinate the backup process. The consistency
of data is a responsibility of the VSS writer and not dependent on Application
Recovery Manager functionality. The backup process of the VSS writers consists of
the following phases:
1. When you select writers and components you want to back up and start a VSS
integration backup, Application Recovery Manager communicates with the
Volume Shadow Copy Service (backup coordinator) to notify that the backup is
about to start.
2. The coordinator identifies all writers that support the VSS feature and passes the
list of available writers and their characteristics (Writer Metadata Document)
back to Application Recovery Manager.
3. Application Recovery Manager examines Writer Metadata and identifies the
volumes that contain the data to be backed up. Then the VSS informs available
writers about selected components.
4. Application Recovery Manager prepares a list of volumes (shadow copy set)
that must be put into consistent state, and passes the list back to the coordinator
for preparing a shadow copy.
5. The VSSBAR agent notifies the writers about the shadow copy creation. The VSS
mechanism ensures that there are no writes on the volume while the shadow
copy is being created.
6. When the writers are fully prepared for the consistent shadow copy backup, the
VSSBAR agent passes shadow copy creation requests to VSS.
7. After the shadow copy set is created, the VSSBAR agent coordinates the VDS
agent to gather information on the created replica that is needed for instant
recovery.
8. After the information is stored to the internal database, the replicas are
unpresented from the backup system. All replicas are set to read-only and are
unpresented from all systems to protect the backed up data, unless you specify
to mount the replica on the backup system.
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