HP Data Protector A.06.11 Integration Manual page 154

The Data Protector Volume Shadow Copy integration provides a unified
communication interface that can coordinate backup and restore of an application
regardless of their specific features. With this approach, a backup application does
not need to handle each application to be backed up specifically. However, the
production application as well as the backup application must conform to the VSS
specification.
Figure 53 on page 155 and Figure 54 on page 155 show the differences between the
traditional backup model and the model with the Data Protector Microsoft Volume
Shadow Copy integration.
154 Integrating Microsoft Volume Shadow Copy Service with Data Protector