How do you back up PVE and PBS servers themselves?

I saw that physical server backup is on the roadmap. Are there a set of directories I can backup and restore? I see the /etc/pve on PVE /etc/proxmox-backup directory on PBS, but are there more that I should include?

Also, what would the restore process be? Do a regular install and then untar the backup directoris over that?
tia