I currently have an old 2006 Mac mini that isn't really supported any longer. I would like to transition this box to be a small home server that runs Unifi and Librenms on Ubuntu. I am trying to create a bootable USB drive as my DRD rom is dead, but once I try to boot to the drive the Mac doesn't see the drive. Could someone assist me with creating a bootable drive so I can load Ubuntu on this Mac.