4. PBS Container on TrueNas Scale

Here we will setup PBS on top of Truenas Scale as a container. Why would you do this ? well if you run both proxmox pve and run a Truenas VM or bare metal then you have two different systems to backup. You want to backup your VM's and you want to back up your TrueNas datasets. Both are optimised for running a second bare metal Proxmox PBS and a bare metal Truenas instance. However, this means you need to get two devices. The middle ground is get 1 extra host where TrueNas and PBS both have direct access to the zfs pools instead of having ZFS on top of ZFS.

Now, ZFS on top of ZFS happens if you have a second PVE instance on which you run a PBS and TrueNas Scale VM. Then you need at a minimum at least 2 drives one to pass through to the PBS VM and one to the TrueNas VM. If you only have one storage drive

Source: Why run PBS on Truenas ?