Restoring Files; Vss Database - HP Data Protector A.06.11 Integration Manual

1. Data Protector first restores the metadata, which was collected during the backup.
Then it examines the metadata to identify the backup components and determine
the restore method. It also checks if restore to specific volumes is possible.
2. Data Protector connects to the coordinator (VSS service) to notify that the restore
is about to start, which in turn communicates with the writer. Data Protector
restores the data from the backup media to the locations specified in the backup
metadata. During the restore, Data Protector follows the writers' instructions
regarding any additional checking or processing specified in the WMD.
3. After the data are successfully restored from the backup media, Data Protector
informs the coordinator that the restore is completed and the writers can now
access the newly-restored data and start the internal processing, for example
recovery.

Restoring files

For a successful restore of a VSS component, all files comprising this component must
be restored. If a restore of a single file fails, the restore of the a whole component
fails. Data Protector offers an additional restore mode for restoring single files that
does not use the Microsoft Volume Shadow Copy Service, thus solving this problem.
This mode can also be used for restoring to systems that do not support VSS or do
not have a VSS writer installed.
When restoring files or a group of files, DMA is started and the files are restored
using the standard Data Protector filesystem restore procedure.
IMPORTANT:
As the file restore mode does not utilize VSS services, additional tasks that are performed
after a component restore – such as database recovery – are not performed and your
application data may be left in an inconsistent state, requiring additional manual
procedures before the application is recovered.

VSS database

The VSS database (VSSDB) is an extension to the Data Protector internal database
(IDB) on the Cell Manager. It holds the VSS integration-specific information about
the VSS backup sessions and their replicas. The stored information can be used for
the following purposes:
• Instant recovery
• Data mining (you can save backup components and writer metadata documents)
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