If your backup software is not aware of the Microsoft Volume Shadow Copy Service (VSS), you can use Pervasive Backup Agent with your backup software. The VSS framework is included with Windows Server 2003 and newer operating systems.
If your backup software is VSS aware, Pervasive PSQL VSS Writer is automatically invoked during VSS backups. You do not need to use Pervasive Backup Agent if your backup software is already VSS aware.
Pervasive Backup Agent is an optional product included with Pervasive PSQL v11 SP3 Server. Pervasive Backup Agent is not included with Pervasive PSQL Workgroup. Backup Agent is offered for purchase as a separate product for use with Pervasive PSQL Workgroup.
For details on Pervasive Backup Agent, see Pervasive Backup Agent Guide, which is available on the Pervasive Software Website (
http://www.pervasivedb.com).
During VSS snapshots, Pervasive PSQL VSS Writer quiesces all disk I/O write activity to all Pervasive PSQL data and transaction log files, regardless of the volume on which they reside. After the snapshot is taken, Pervasive PSQL VSS Writer allows all disk I/O to resume; this includes any writes that were deferred during the quiesced period.
Pervasive PSQL VSS Writer never quiesces disk I/O read activity, allowing normal database processing to continue during the quiesced period as long as writes are not required. Pervasive PSQL VSS Writer operates normally during the backup phase, although performance may likely be reduced due to the backup activity of the VSS service and VSS Requestor.
When Pervasive PSQL VSS Writer is called and files are in Continuous Operations, be aware that VSS Writer operates independently from any Continuous Operations. If files are in Continuous Operations when a VSS backup is in progress, view PVSW.LOG after the backup completes. Ensure that the Frozen and Thawed states completed successfully and that the data is in a well-defined and consistent state.
The 32-bit version of Pervasive PSQL VSS Writer can be used with Pervasive PSQL Server 32-bit and the database accelerator Xtreme I/O (XIO). See
Xtreme I/O Driver in
Advanced Operations Guide.