Volume Shadow Copy Service
This option is effective only for Windows operating systems.
The option defines whether a Volume Shadow Copy Service (VSS) provider—either Acronis VSS or Microsoft VSS—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 10. Data consistency, in turn, ensures that the application will be recovered in the correct state and become operational immediately after recovery.
The preset is: Create snapshots using VSS
Acronis Backup & Recovery 10 will select the VSS provider automatically based on the operating system running on the machine and whether the machine is a member of an Active Directory domain.
Create snapshots without using VSS
Choose this option if your database is incompatible with VSS. The data snapshot will be taken by Acronis Backup & Recovery 10. 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, to ensure 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.