Configuring Barracuda Backup Agent to use Microsoft VDI to Perform Incremental SQL Backups

As I may have mentioned, my company is currently testing out a Barracuda Backup Appliance and I have been going through the ropes of getting everything operating the way it needs to be for our environment.  One issue I came across along the way was that my SQL machines were not having their transaction logs truncated when I ran a “Microsoft SQL” backup.  Come to find out that the Barracuda Backup Agent is by default configured to use Microsoft VSS, which has it make Full and Differential backups rather than Full and Incremental backups created when using Microsoft VDI.  For a good explanation of the difference between backups, read this MSDN explanation.  The following is a good definition of Microsoft VDI provided in the comments here:

“SQL Server provides an API called Virtual Backup Device Interface (VDI) that enables independent software vendors to integrate SQL Server into their products for providing support for backup and restore operations. These APIs are engineered to provide maximum reliability and performance, and support the full range of SQL Server backup and restore functionality, including the full range of hot and snapshot backup capabilities.”

Mind you the differential is perfectly fine if all of your databases are in Simple recovery mode.  If your databases are in Full recovery mode, incremental backups are the way to go from what I understand.  This is also Barracuda’s recommendation (found here).  So, to fix this issue we have to manually change the configuration file for the Barracuda Backup Agent on the SQL server itself (Barracuda KB Article).

Start by stopping the Barracuda Backup Agent service.  Then navigate to C:\Program Files\Barracuda\Barracuda Backup Agent\config and edit the config.ini file.  Under the configuration section add the following (add a configuration section if it is not present):



Save and close the file and go back to services and start the Barracuda Backup Agent service.  Now go to your Cloud Control and navigate to your backup schedule.  Under “Items to Backup” expand your SQL server and you should now see Microsoft SQL Server and Microsoft SQL options.  Clear the Microsoft SQL option and select the Microsoft SQL Server and save your settings.  You should now be good to go!  The Microsoft SQL option will remove itself from the Items to Backup options moving forward as seen below.

VMware ‘VssSyncStart’ operation failed: IDispatch error #8462 (0x8004230e)

At work I am currently doing a trial run with Barracuda’s Backup Appliance.  I got it racked and configured (with quite a bit of annoyance since you have to call their support to bond NICs) and kicked off the initial full backup and received the following “Unable to quiesce disk” errors.

Since I was already working with Barracuda’s engineer on the LACP and some upload throttles, I asked his opinion on the matter.  Long story short he pretty much told me to investigate VMware and I’ll probably find the issue, and that I did.  When I tried to manually take a snapshot selecting the “Quiesce guest file system (Needs VMware Tools installed)” I received the following error:

The guest OS has reported an error during quiescing. The error code was: 5 The error message was: ‘VssSyncStart’ operation failed: IDispatch error #8462 (0x8004230e) 

Digging through the VMware forums I found that my issue was with the Volume Shadow Copy Services Support part of VMware Tools.  I uninstalled VMware Tools and re-installed, but instead of selecting a complete installation I selected Custom and did not install the Volume Shadow Copy Services Support.

Once that completed installing and I restarted the effected machines, the issue was resolved!