The example of the hardware provider is disk array, which has its hardware mechanism of providing point-in-time state of a disk. A software provider operates on physical disks and uses software mechanism for providing point-in-time state on a disk. The system provider, MS Software Shadow Copy Provider, is a software mechanism, which is a part of the Windows Server 2003 operating system.

The VSS mechanism guarantees that all hardware providers will be offered for creating shadow copy before all software providers. If none of them is able to create a shadow copy, VSS will use the MS Software Shadow Copy Provider for the shadow copy creation, which is always available.

Data Protector and VSS

The Volume Shadow Copy service enables coordination among the backup application, writers, and shadow copy providers during the backup and restore process.

Figure 89 on page 292 and Figure 90 on page 292 show differences between the traditional backup model and the model with the VSS coordinator.

Concepts guide

291