I've installed Fedora on a new SATA SSD drive for my MacBook Pro, and when installed into the laptop, it boots perfectly (and runs wonderfully!). However, I want to boot from it externally until I'm ready to make the switch from OS X, so have mounted the drive in a USB caddy.
Unfortunately, it doesn't boot from there, when powering on and holding the Alt key. This question suggests installing rEFIt to get it to boot; however, my other research on the web makes me think rEFIt tends only to be used where multi-boot is required.
Since my new drive boots perfectly well when installed in the laptop, I'm hesitant to install a new boot loader, in case I break something! Can I put rEFIt on a memory stick and boot from that to then boot from the SSD drive in another USB port? Or, is there a much simpler solution I have overlooked?
PostScript: I've not tried it yet, but if I put the Linux/SSD drive into the laptop, will the OS X drive be recognised as a USB boot device?