I'm trying to make a bootable USB stick on my MacBook Pro Retina 10,1 that I hope will also boot a wide range of other computers. I followed the instructions here: http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-mac-osx
I'm able to boot into the installer and do a successful partitioning and install onto a second USB stick. But when I reboot with the option key down, the new Ubuntu disk never appears as a startup disk option like the installer did. I have no idea how to boot it any other way. What am I doing wrong?
(Note: during partitioning, I created a 300 MB EFI partition on the USB stick and told the installer to use that for the boot loader. Is this correct?)
I'm finding a lot of contradictory and complicated instructions out there about this with new MacBook Pros: Bootable Ubuntu USB Stick just not possible on Macbook https://help.ubuntu.com/community/MacBookPro11-1/Saucy
Also note, I'm not trying to dual boot OS X and Ubuntu from the same drive. I just want a bootable USB stick with some custom software that I can use occasionally on this and other machines.
Thanks for any tips!