local backup with zfs. zfs backup procedure

Hi At the moment I am using 2 Physical Servers. Each with 2 VM's running, Total 4 VM's. Each Server has 3 Hard Drives. 1 X 2TB and 2 X 4TB The 2TB Drive holds Proxmox and the VM's On Each Server The 4TB (ext4) Drives Hold Backups (Adding as Directories) from both the local Server and the...