HP B6960-96035 - Manual (Page 293)

VSS benefits
The advantages of using Volume Shadow Copy service are as follows
• A unified backup interface for all writers.
• A unified backup interface for all shadow copy providers.
• Writers provide data integrity at application level. Intervention from the backup
application is unnecessary.
Data Protector supports the Microsoft Volume Shadow Copy service at two levels:
• Within the Microsoft Volume Shadow Copy service integration, Data Protector
provides a shadow copy backup and restore of VSS-aware writers, including
ZDB and instant recovery functionality.
• Within the Disk Agent functionality, Data Protector provides VSS filesystem backup.
The Data Protector VSS integration supports a consistent shadow copy backup only
for VSS-aware writers. Consistency in this case is provided by the writer. Whenever
applications are not VSS-aware, a shadow copy is created. The consistency of the
shadow copy data is not guaranteed at application level, however, it is improved in
comparison to a non-VSS filesystem backup.
The table below outlines the differences between using Data Protector VSS integration
backup, VSS filesystem backup, and non-VSS filesystem backup:
Table 14 Benefits of using VSS
Non-VSS filesystem
backup VSS filesystem backup Data Protector VSS
integration backup
If files are open, backup
may fail. No open files. No open files. Open files
If files are locked,
backup skips them. No locked files. No locked files. Locked files
None (inherent). Crash consistency state
(in the event of a power
failure, for example). Provided by the writer. Data
integrity
Data Protector Volume Shadow Copy integration
The Data Protector integration with Microsoft Volume Shadow Copy service provides
full support for VSS-aware writers. This includes automatic detection of VSS-aware
Concepts guide 293