Q - After PSQL 11 SP2, are both Backup Agent or Volume Shadowing Service (VSS) included for my backup purposes? Which one should I use?
A - Based on Pervasive's recommendation:
Which Backup Solution Should I Use?
If you are running PSQL on a Windows platform and your backup software is VSS-aware, Pervasive recommends using the PSQL VSS writer as part of the VSS framework. If your backup software is VSS-aware, PSQL is automatically invoked during VSS backups.
If your backup software is not VSS-aware, the best choice is to use Backup Agent with your backup software.
How to Install Backup Agent
You can use PSQL 11 SP2 or after Windows Installation Package to install Backup Agent. You can also download from the www.pervasive.com website.
How to Use Backup Agent
Most of the backup software offers pre and post script. Assuming you are using 64-bits, in the pre-script area, you will add the following line to start Backup Agent:
In the post-script area, you will add the following command to end Backup Agent:
Backup Agent Precaution
Backup Agent works with backup software to ensure accurate, reliable point-in-time recovery for partial or complete backups. Backup Agent works transparently during a backup session by automatically placing open files into a continuous operations mode while the backup is in process. Any changes to the files that occur during the backup are buffered and applied to the file after the backup is complete.
Through our experience, the main issue we found with Backup Agent is that when a user leaves Backup Agent on after backup finishes, it not only creates large delta files that can slow down performance, but can also compromise the integrity of your data. In addition, we found that any Elliott user will not be able to create any work file while Backup Agent is on.
This is because Backup Agent will try to create a delta file (extension ^^^) for any changes after Backup Agent starts. But the nature of “Work File” is to wipe out the file and start anew, which is incompatible with the Backup Agent delta file concept.
If Backup Agent is started at nighttime, when no users are in the system, then this work file conflict issue won't occur. But if Backup Agent did not complete for some reason, then the next day users will run into the issue when running the process that will require create work files. Below is an example of what happens when a user tries to run the Elliott Financial Statement, which requires the creation of a GL Statement Work File. If Backup Agent is started, then the user will receive the following error:
Btrieve Error 025 on GL Statement Work File
Therefore, if you wish to use Backup Agent each night to perform backup, you should make sure that Backup Agent is turned off the next day. You can do so by using this command line utility:
Or you can use the GUI utility, pvbackupgui.exe:
The above example shows that Backup Agent was not started on this machine.