I've installed rEFInd and it works. I've allocated free space on my internal harddrive. I've burned an Ubuntu 13.04 DVD and I'm using an external DVD drive. rEFInd recognizes the DVD but when I select it in the rEFInd menu, it says the firmware cannot boot from the dvd. It also says that rEFInd doesn't support booting from external medias.
What are my options?
An idea I had was to setup another partition on my internal drive and copy the install files there and then (somehow) boot from that partition. Not really sure how to do that. Ideas welcome.
I have a mid-2010 macbook pro (internal dvd replaced with HDD).