So I have a Macbook, and it's dual-booted....I almost never use MacOS, and I like Windows, but Rails is close to impossible to install on it, and so far my experience with it on OSX hasn't been that much better. I've decided to switch to Linux as a development system, as I've had very good experiences doing so in the past.
The obvious answer is to triple boot, but I don't really have enough HD space for doing that well, and when I investigated the process, it seemed even more complex than trying to get rails and MySQL to run on Windows correctly. So I decided I would simply take an older external USB hard drive, and install Ubuntu (or Mint, or whatever, it doesn't really matter, as long as it's Debian based) to my drive. I tried booting into a live CD, partitioned the drive (ext4), then installed Linux to it. So far so good, but now, I cannot select it on the startup screen - it doesn't appear to Apple's bootloader as a bootable drive. So how do I go about making this work?