Proxmox is using a ZFS raid1 storage. On there, a disk has been created for a VM. This disk is currently formatted as ext4. Does that make sense? I guess its up to me. I'm just double checking. I might format the disk to ZFS, since it has the ability to check integrity.
Which disk? The virtual disk on your ZFS pool? You shouldn't run ZFS ontop of ZFS. Etx4 ontop of ZFS would be fine.
Exactly, it's a diskfile on top of the ZFS storage. It's currently formatted with ext4, so I will keep it like that. Thanks.