VMs with vTPMs cause entire jobs to not keep CBT data

[Amarokada]

Ok, this might just be a 6.8.0.5 issue, I don't know until we've upgraded our Nutanix cluster. But since we put this platform together and migrated over 1400 VMs from Hyper-V we've noticed something odd about the snapshots Veeam uses for the next day CBT.

We would have say 100 VMs backing up fine in a single job (backup mode, not snapshot mode), and each VM would leave behind the single snapshot from the last backup to be used by the backup the next day for CBT. This is critical when you have so many VMs to backup each night, because when there is no snapshot the incremental backups are much slower.

Then we started building new VMs and adding them to the backup jobs, and we found all of a sudden every VM in that backup job would not keep it's snapshot anymore. This showed in the Veeam interface (under snapshots) and the nutanix prism interface. Basically the snapshot was deleted once the backup had been processed. This slowed down our backups so much we had to move the offending new VMs to their own jobs so they wouldn't interfere with the other VM backups.

I then spent some time trying to track down what was different about these new VMs, and eventually have found it's because they were created with the vTPM option switched on. When removing this (VM has to be powered off first) and then deleting the backup chain, the backup would work as expected and the snapshot would be left behind for CBT.

Is this known to the Veeam techs here? Or possibly it will be put down to the 6.8.0.5 Nutanix version.

[ronnmartin61]

I don't believe this is something we've run across before. Let me do some checking...

[Amarokada]

Just to add a bit more data to this, when this issue happens the Veeam AHV appliance shows an error on the dashboard, which relates to the nightly backup repository scan. It will show an error for each VM that has a backup with vTPM like so:

12/3/2024 8:57:47 AM Error Failed to import backup 88acbe18-6542-4400-834a-b13c638a8ea8. Error: Object reference not set to an instance of an object. —

And you will not find the VM in the "Protected VMs" section, so the AHV appliance can't cope with these backup files. However in the VB&R interface it will show the backup succeeded and you see the VMs in the disk section.

[ronnmartin61]

@Amarokada we've discussed internally and believe this condition may be fixed in the v7.0 release that dropped yesterday