Running NTBackup in a pre-freeze script

[chowderhead]

Hi there,

I thought I'd be clever and incorporate NTBackup into the pre-freeze backup script of an Active Directory VM. What the script does specifically is run an NTBackup of the system state to the local disk, and then copy the backup file to a remote file share. If an error is generated while running the script, the pre-freeze script returns the error number prior to exiting (which means that in the event of any sort of NTBackup error, the nightly regular backup of the VM will be not occur). I tried this idea out in the test environment, and it works most of the time. However, occasionally a VSS error 12301 (no response from GatherWriterStatus) is generated, but despite the error the NTBackup completes just fine. So I changed the pre-freeze script to ignore all error instances of 12301 (a 0 is returned instead).

So what I what to know is, is this a great idea or a very bad idea? I figured everything would be okay because the NTBackup should complete prior to when the disks are quiesced (due to the nature of the pre-freeze script).

[dconvery · Accepted solution]

First off, Welcome to the Forums!

What a great idea! I have recommended running NTBackup for DCs for a long time - since win2000 days. It never even occured to me to add it to the pre-freeze-script.

As for your VSS error, it is not recommended that you use the quiescing on transactional systems, like AD, SQL and Exchange. I would add the "-Q 0" option to your vcbMounter command for this VM. (Undocumented, means no quiesce - Thanks to depping for this one!)

If you are doing VCB backups with an integration kit, you could also uninstall the VSS provider and the sync driver on this VM.

Dave Convery

VMware vExpert 2009

Careful. We don't want to learn from this.

Bill Watterson, "Calvin and Hobbes"

[chowderhead]

Thank you for your feedback. So my idea isn't crazy--that's good! I couldn't find any references on the internet to other people doing the same thing (i.e. putting NTBackup in a pre-freeze script) so I didn't know if there was a good reason not to do so.

So as far as the VSS error, you are saying that it has nothing to do with NTBackup. Rather it has to do with VSS and transactional systems, right? (In other words, even if I were to remove NTBackup from the pre-freeze script, there is still a chance that the same VSS error may crop up at some point in time).

[dconvery]

I would imaging the VSS error is from the VCB quiesce process. That's when I usually see it.

Dave Convery

VMware vExpert 2009

Careful. We don't want to learn from this.

Bill Watterson, "Calvin and Hobbes"