3 Replies Latest reply: Jan 12, 2006 11:32 AM by Marc D
Marc D Level 2 Level 2 (320 points)
I partitioned my external back-up drive and create a boot partition on which I installed Tiger.

How can I test that I can actually boot from the external drive if my internal HD were to crash? There must be a key combination to use during start-up to force it to boot from the external drive. Anyone?

14 iBook G4 [1.42/60/1.5GB/Super] & eMac G4 [800/60/1GB/Super], Mac OS X (10.4.3), Escaped Windows in 2003!
  • matthew whiting Level 4 Level 4 (3,375 points)
    Hi Marc

    Hold down the option key when you start your Mac. You will then be able to choose which drive to boot from. Or, of course, you can select the drive in System Preferences>Startup Disk.

    Matthew Whiting
  • Charles Dyer Level 4 Level 4 (2,620 points)
    There are two simple ways to boot from an external drive. (Note: it must be a FireWire drive. OS X will not boot from a USB drive.) (Second note: if you want to boot one of the new Intel Macs, you must have formatted the drive from an Intel Mac. A drive formatted from a PowerPC Mac contains boot code which knows PowerPC Macs, only. A drive formatted from an Intel Mac has boot code for both Intel Macs and PowerPC Macs.)

    Method one: on startup hold down the option key and keep it held down until you see a blue screen. Several icons will appear on the blue screen; the icons with the blue 'X' on them will be OS X-based startup volumes. Double-click on one of them and the Mac will boot from that volume. If your Mac is capable of booting OS 9 and an OS 9 boot volume is available, it will show as an icon with an orange '9'. Bootable CDs or DVDs will also show up, they just take a while to appear.

    If you use that method, then the next time you boot your system will boot from your normal boot volume so long as you didn't change anything while booted.

    Method two is equally simple: go to System Preferences, go to Startup Disk, select the volume you want to boot from, reboot, you're golden. If you use this method, you will continue to boot from that volume until you change it by going back to System Preferences. (Assuming that the volume is available; it it's an external volume and you disconnect it before booting, you'll boot from the internal volume instead... if the internal volume is bootable, that is.)
  • Marc D Level 2 Level 2 (320 points)
    Thank you both!