OK, let's pretend my internal hard drive failed. I have a bootable partition on my FireWire drive, but the default start-up disk is the internal one. I need access to my backup files or the world will end prematurely. Upon failure, will the Mac: a) automatically look for another disk to boot from? (and therefore i don't need to worry) b) need to be told to boot from the FireWire drive? (and therefore I really should try to find out before it happens) I note that this has been discussed to some degree here but not to a satisfactory conclusion. Apparently you can press Cmd-opt-shift-delete during boot up to force the internal drive to be overidden. But when I try that, the computer just boots from the internal but in safe mode. I held down the keys as soon as I heard the chime and let go once the Apple appeared. What am I doing wrong?