I have what seems to be an odd anomaly on my hands. I'm trying to run Ubuntu 12.04 LTS on my 2010 MacBook Pro. I'd like to run it externally. I used my desktop installation of 12.04 and my 12.04 LTS installation DVD to create a ubuntu start-up disk on an 8GB flash drive. I tested it by booting my MacBook Pro while holding the option key. The usb drive shows up as an EFI boot and boots without a hitch when I choose "try Ubuntu without installing." After confirming that this worked, I assumed a full install of Ubuntu 12.04 on an external HDD would work just as well. Apparently, this isn't true. Using the same boot method, the laptop fails to locate the external drive with Ubuntu 12.04 on it.
Any thoughts? I've wondered if this is an EFI/Grub2 problem, as the 8GB start-up disk has some boot files that I can't find on the full installation on my external drive.
Additionally, I'm sure rEFIt will get mentioned if anyone responds here. I installed it in OSX Lion months ago; however, my internal HDD appears to be dead, hence why I'm trying to get Ubuntu running on the laptop. In short, I do not have a functioning copy of OSX at the moment. Could this be as simple as dragging/dropping EFI boot files from one disk to another?