These drives can be used as startup volumes, but they will only be bootable if the Logical Unit Number (LUN) is zero.
To determine the LUN of the external FireWire drive, perform the following steps:
- Go to /Applications/Utilities and double-click Disk Utility to open it.
- Select the hard drive to highlight it as shown below.
- Choose Get Info from the File menu.
- Locate the Device Tree text field then locate the number after that follows "/@" as shown below.
If this number is zero, the device should be bootable.
- If the LUN is not zero, there are probably other devices connected to the FireWire bus and one of them already has a LUN of zero.
- If the software utility that was bundled with the drive allows you to assign a LUN, use it to change the LUN of the drive you wish to use to zero and change the other devices to a non-zero number.
- If your software utility does not offer LUN assignment (many of them do not), disconnect the other devices from the FireWire bus so that the drive you want to use is the only device on the FireWire bus.