Booting from a Firewire Disk backup - get Startup Manager to show FW disk

Question

Hi all,
A hint that I have discovered whilst trying to create a backup on a Firewire external Hard disk and boot my eMac from it.
eMac 1.0GHz (ATI), OS X Tiger 10.4.7 and OWC Mercury Elite Pro 40Gb firewire external disk (Oxford 911+ chipset)
I created a bootable backup using both Carbon Copy Cloner and/or Rsyncx on the firewire disk, but with the same results each time - it woudn't boot from startup manager. I was careful to make sure that the disk was bootable and it would boot from the FW disk after selecting it in system preferences/startup disk and restarting. O.K so far.
OS X also offers an alternative boot method using the startup manager at boot time which you can enter by holding down the option key while turning on the eMac until the startup manager comes up. Normally it shows your "macitoshHD" and "repair" hard drives and you can select the preferred boot up drive. According to Apple help it should also show bootable Firewire disks, but I could not get this to happen.
After a bit of trial and error, I found this sequence reveals the FW dive.
. Make sure your firewire external drive is turned on and plugged in to a firewire port on your eMac.
.Power on the eMac whilst holding down the option key (The key with the apple and squiggley thing next to the spacebar)
.Keep holding the option key until the startup manager icons appear.
.Once the startup manager appears, it will take about 30 secs to 1 min to scan for drives.
. Usually icons showing your internal bootable drives will show along with a rescan and continue icon.
. To get the FW drive to show, hold down the option key and click the rescan button (the turned back arrow icon on the left)
.The system will then rescan and find the firewire drives and show their icons as well as the internal drive icons.
. Select the firewire drive (You did give it a unique name didn't you?) and the click the continue arrow on the right.
. Watch the FW drive activity light and you should see lots of flashing and there you are - booting from the FW drive.
I couldn't find any reference in all the help references to holding down the opt key to rescan, so maybe it is peculiar to this eMac?
Give it a try and be sure to let me know if it works for you.
Ian

Answer 1

OK JMVP, but there is something a little strange here.
After I booted the system whilst holding down the OPTION key, startup manager appeared and scanned for drives but only showed the normal internal drives. (By this time I had already released the OPTION key). I clicked the re-scan icon and same thing, still no FW drive. According to all the Apple help files it should show the external FW drive as well.
But, when I held down the the OPTION key and clicked the rescan icon again, it rescanned and showed the internal drives AND the FW drive. Maybe it's an undocumented feature of startup manager, maybe it's peculiar to the FW drive I'm using
I will try to update the firmware, but the manufacturers website says it doesn't need updating to work with Tiger. Other than this minor prob it already seems to be working OK. Just won't show up in the startup manager without rescanning with the option key pressed.
I did notice whilst searching the help files that there is another option to boot from external drives:
Hold down Option-Command-Shift-Delete keys during startup - this will Bypass primary startup volume and seek a different startup volume (such as a CD or external disk). It didn't work in my case.
Curious?
eMac (ATI) Mac OS X (10.4.7) Mac Newbie