My initial thought is they used a non-GUID partition setup. I recently converted a NTFS external to HFS+ and went to install a copy of the OS on there as an emergency backup. Forgot to change the partition type from Master Boot Record, and it wouldn't let me install the OS until I fixed that. But if I had used something like SuperDuper! it might not care.
I have a Intel Dual-Core Intel Xeon. I boot from FW drives all the time. A client came in with their OS on a WD My Book Studio LX. I plug in via FW 800, but holding the option key on boot does not display the clients FW/OS drive. I can go into startup disk, select their drive from there, but when the computer restarts I get to the grey Apple screen and it just stays there spinning and then the Mac restarts itself.
One strange addition; when I boot to my good OS, their drive shows up with an internal drive icon as opposed to the regular FW icon. they brought their new 8-core system off their bus and we are able to boot off that computer from the FW drive no problem.
Any thoughts as to why it may not be able to boot?
- one additional bit of info; on the same Dual-Core I was running another clients 8-core OS clone earlier the same day, but he had a raw drive so I pulled our OS drive and installed theirs. Obviously internal/external shouldn't matter, but I wanted to make clear that I had just run an 8-core OS on the same Dual-Core Intel.
My only thoughts might have something to do with our Dual-Core set to 32-bit EFI and the Western Digital FW drive was cloned from a 64-bit system? Just a guess and I'm off to see what my Dual-Core EFI is set at. I'm probably looking in the wrong direction, which is why I'm asking here