If you end up with a second proxmox server with its own storage for redundancy in a cluster then ZFS is great. You can mirror each VM. The only issue is the ZFS storage needs to be named the same. But it can be a different size or media.

I accidentally posted a link to some right wing borderline racist article which sounded sensible on first skim reading it. Commentators noted this. I apologized for not reading it carefully or noticing the other associated articles and the other Lemmy users were understanding. Just my experience but I think a nicer atmosphere prevails.