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Old 07-21-2009, 03:37 AM
chris_johnsen chris_johnsen is offline
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Join Date: Jan 2007
Posts: 79
I have never heard of a Mac booting off of an drive with solely an MBR partition (discounting the GPT/MBR hybrid that Boot Camp can create), but I suppose it is possible (after all, Intel Macs reportedly can boot from APM, it is just not officially supported/advertised).

Do you usually have both external drives connected to the system? Are the volumes on both exernal drives named similarly? Maybe you misread it as booting from a volume on the Verbatim but it was actually booting from the OWC.

When determining the startup disk for the computer as it is currently running, you should always look at Startup Disk in  > About This Mac.

Are you using the "Restart from " or the "Set as Startup Disk" options in SuperDuper!? Maybe those options uses bless in a way that can configure the startup disk to use a partition that System Preference's Startup Disk preference pane and the boot-menu (boot + Option) will not allow the user to choose (it is fairly common for the GUI to offer fewer options than the underlying CLI/API actually supports).

It could be that the Open Firmware was actually configured to boot from a partition on the MBR Verbatim disk. This is speculation, but in such a situation, the firmware might notice that it can not possibly startup from that volume. Faced with this "insane" configuration, it might try to boot from a "normal" volume (like one on the internal disk). That would cause System Preference's Startup Disk to show that a particular volume is selected while the system consistently boots from some other volume. This is another reason to use About This Mac to check the actual startup disk. Such a hypothetical "boot-time decision" by the firmware or even a normal Option-boot by the user can make the actual startup disk different from the configured startup disk.

Assuming the Verbatim disk is otherwise bootable (good chipset), you will probably have to repartition it as APM before any of its volumes will work reliably as the startup disk. If you can not stand to erase the whole disk (what Disk Utility will do), you could look at iPartition.
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