Volume Shadow Copy Service

This option is effective only for Windows operating systems.

The option defines whether a Volume Shadow Copy Service (VSS) provider has to notify VSS-aware applications that the backup is about to start. This ensures the consistent state of all data used by the applications; in particular, completion of all database transactions at the moment of taking the data snapshot by Acronis Backup & Recovery 11. Data consistency, in turn, ensures that the application will be recovered in the correct state and become operational immediately after recovery.

The preset is: Use Volume Shadow Copy Service.

Use VSS

With selected Use Volume Shadow Copy Service, choose a snapshot provider from the following list:

• Hardware/software - Select automatically (selected by default)

  VSS will use the hardware-based provider that supports the source volume. If none is found, VSS will use a software-based provider.

• Software - Select automatically

  VSS will use the software-based provider that supports the source volume.

• Software - Acronis VSS Provider

  VSS will use Acronis VSS Provider for taking snapshots.

• Software - System provider

  VSS will use the system provider (Microsoft Software Shadow Copy provider) for taking snapshots.

• Software - A software provider

  VSS will use any software-based provider that supports the source volume.

• Hardware - Select automatically

  VSS will use the hardware-based provider that supports the source volume. If no hardware-based provider is found, snapshots will be created by means of Acronis Backup & Recovery 11.

Do not use VSS

If you select Do not use VSS, the data snapshot will be taken by Acronis Backup & Recovery 11.

Choose Do not use VSS if your database is incompatible with VSS. Backup process is fastest, but data consistency of the applications whose transactions are not completed at the time of taking a snapshot cannot be guaranteed. You may use Pre/Post data capture commands to indicate which commands should be performed before and after taking the snapshot. This ensures that the data is being backed up in a consistent state. For instance, specify pre-data capture commands that will suspend the database and flush all caches to ensure that all transactions are completed; and specify post-data capture commands that will resume the database operations after the snapshot is taken.

Volume shadow copy writers

Before backing up the data of VSS-aware applications, make sure that the volume shadow copy writers for those applications are turned on by examining the list of writers that are present in the operating system. To view this list, run the following command:

vssadmin list writers

Note: In Microsoft Windows Small Business Server 2003, the writer for Microsoft Exchange Server 2003 is turned off by default. For instructions on how to turn it on, see the corresponding Microsoft Help and Support article.