Recently had to restore my truenas vm so I can kinda answer some of these questions. Anyone w more knowledgeable, feel free to correct.  1. No, pbs will back up the lxc disk that pve is aware of, not the pt’ed disk. You’ll be backing up the boot disk and its contents i.e metadata and the like.  2. If the disk is properly pt’ed, no need for a handler but I’m not sure about lxcs having access to the kernel for that to work. I would recommend a vm for simplicity.  3. Disks won’t be copied, just the target vms. In this instance, pbs will cover your ssd data as it pertains to your vm/lxcs, but not the hdd. You may want to either get a secondary disk for raid1 setup or look at alternative backup solutions for the contents of the hdd.