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

 

Data Protector VSS

VSS filesystem backup

Non-VSS filesystem

 

integration backup

 

backup

 

 

 

 

Open files

No open files.

No open files.

If files are open, backup

 

 

 

may fail.

 

 

 

 

Locked files

No locked files.

No locked files.

If files are locked,

 

 

 

backup skips them.

 

 

 

 

Data

Provided by the writer.

Crash consistency state

None (inherent).

integrity

 

(in the event of a power

 

 

 

failure, for example).

 

 

 

 

 

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

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