Forgot to give an update:

Evidently that backup image was corrupted when I checked it in Proxmox Backup Server’s panel. Redid the backup and rechecked it and it said all was fine. I added that crontab that automatically moves those files to a spare SSD I have sitting around on the server.

I think that minor corruption happened because I originally had the hard disk mounted on the hypervisor level before it gets pulled away and passed through to the VM when it boots up. That’s what I’m hoping to be the case anyways.

I used to have it set to backup full VM images on Proxmox itself. Now I remotely backup the files to a proxmox backup server that I run in a VM for which I passed the hard disk through to, because the backups there can be deduplicated and take soooo much less space.

I’ll check on it here in a week or so to see if the VM image backup ends up corrupted again. I need to find a way to have it ping me if a backup fails too. Currently Proxmox only supports email afaik, but I think I can write a bash script that polls my logs and then pings my phone using ntfy or whatever is the cool new hip software in town for notification needs.