Veeam backup of PVE vm on spinning disks ceph issues

[squebel]

Hello, case 08166423 is open with Veeam support. We are running 12.3 and plugin version 1.5 and we have a couple of PVE clusters running Proxmox CEPH but using a hybrid setup with spinning disks. In some situations, the snapshot that Veeam is creating of that vm is causing major IO performance issues. I am being asked to immediately upgrade to the latest version hoping that it will fix the issue. Is there anything in the newer version and plugin that fundamentally changes the way a PVE vm backups are run?

[vnikiforov]

Hello,

No - the general backup flow is the same. The upgrade advice still stands, though. V12 passed End of Fix in November 2025 under the product lifecycle policy, so bug fixes now ship on V13.1+ only, and there were snapshot handling changes between PVE plugin versions.
With 13.1 expected in the coming weeks, I'd go straight to that. If the IO impact reproduces on the latest version, open a new support case with new logs from a new version.

[squebel]

I deployed a fresh v13 instance using the latest VBR appliance and set up a backup job to backup a single Windows vm on the proxmox cluster with a worker on the same node as the vm. IO impact is still the same. The vm locks up hard after a few minutes to the point it has to be powered off and restarted after the backup job is stopped and cleaned up.

[vnikiforov]

Hello,

Please be advised, It was recommended to test that on the upcoming Veeam Backup & Replication 13.1. If the results are the same, I recommend opening a support case with logs from the 13.1 version. This will allow us to engage proper support resources relevant to the case.

[squebel]

Vladimir, are there functionally different processes behind the scenes on how the backup process works for Proxmox in 13.1 that could potentially result in less impact to the running vm? If not, why would 13.1 make any difference?

Also, we're aren't blaming Veeam. We do know that the design of this PVE cluster is not optimal when it comes to the underlying disks but we're just trying to figure out the best way to protect the data without causing impact. And we do not want to have to look at other options; we want Veeam to work for this.

[vnikiforov]

Hello,

Please refer to my initial message: There are no fundamental differences, BUT in v.13.1 there were many changes including PVE plugin, specifically related to snapshots handling, which might have effects on the IO operations. In any case, as per Veeam support policy, the latest version is required to be used to consider changes. That is why testing that on the latest version (once it is released) and 13.1 logs and new case are needed.

[squebel]

Are you able to provide some information on what those "many changes including PVE plugin, specifically related to snapshots handling" means and why it could possible have effects on the IO operations?

[vnikiforov]

Hello,

Unfortunately, not, but I strongly recommend you try the new release. And if the issue persists, we have all the resources to address it.
I can't speculate on the root cause or the potential effects, as no research has yet been done on a technical side, and on this forum we do not provide technical support.
That is why I recommended the appropriate approach to handle that.