I worked with ChatGPT on this for a bit. We have narrowed it down to an issue with the NFS Storage that I ship the backups to. "When you recreated storage and moved data back, OMV is technically exporting a different underlying filesystem object than before. NFS clients that had an old handle cached (your XCP-ng host) try to access it and get ESTALE. That explains the initial backup errors and why deleting/re-adding the SR is failing now." I had to remove the NFS storage from XCP-ng, then delete the NFS share from OMV, then add the NFS share back to OMV, and then add it back to XCP-ng. I probably could have resolved this with a reboot, but I didn't wanna. This issue is resolved now.

@nuentes For reference, the “PCI Passthrough” that was referenced involves buying a USB PCI card, and passing the card through. If you need any help getting the script up, just respond here and I’ll do what I can to help. My comments in the script arent immaculate

@olivierlambert Well that was easy. Much appreciated!

@florent any other ideas in order to resolve this?

On a thin volume, it will only use the "real" space in the VM, so if you are using 40 or 50GiB, yes it will fit on the 78GiB storage