Dual Processor G5 - I just installed an external S-ATA card (Sonnet Tempo) and drives. I could format, stripe RAID and install the system on the external drives. Even in the system preferences I am able to select the external S-ATA as the startup disk. But it won't startup from that disk and consequently I can't reload Motion 1 back unto my system (which is my ultimate goal.)
When I restart with the option key held down my only choice for startup disk is my original internal Hard Drive.
Not much of a mystery on the surface: The external RAID probably requires some bits at startup before it can be seen or accessed; could be the drivers for the card or the RAID driver. Are you sure the card, drive or RAID software mfr has promised you the ability to start from the external RAID?
Sorry not be able to give you a definitive replay, my RAID experience stopped several years ago when we replaced our SCSI junk with Firewire. But back then, we could not start from the RAID because there was no way for the Macintosh to know it was even connected until after the System loaded.
This is my standard sigfile so do not take it personally: "For crying out loud, read the freakin' manual."