Convert a drive from Apple Partition Map to GUID

Oct 30, '07 07:30:05AM

Contributed by: pootify

While upgrading the laptop hard drive on my Macbook, I inadvertantly partitioned the new hard drive in the "Apple Partition Map" mode, which is reserved for PowerPCs. The normal partition type for a Intel Mac boot drive is GUID. My Intel Macbook still booted from this drive, but having my hard drive in Apple Partition Map mode had two severe drawbacks:

  1. I couldn't install Boot Camp.
  2. I couldn't upgrade to Leopard!
I read a couple guides online, and they involved simply copying your user folder and reformatting the drive, but I wanted a method that copied absolutely everything so that I wouldn't have to install my horde of apps. So, here's how I went from an Apple Partition Mapped drive to a GUID drive for Leopard, without losing any of my data, settings, or having to re-install my applications.

Requirements

Steps
  1. Formatting your external: Plug in your external drive and back up anything that's already on it. Go to Disk Utility, select your FireWire drive and in the right side, click on the Partition tab. Click on the Options... button and select GUID as your Partition Type. Lastly, click on the Partition button to format/partition your external drive as GUID. Approx time: Less than five minutes.
  2. Copying your data: Once it's formatted, run SuperDuper. For your source in the left dropdown, select your original, internal hard drive. For the destination in the right dropdown, select your external drive. For the "using" dropdown, select Backup - all files. Click on the Options button, and then in the During Copy dropdown, select the first option that says Erase, then copy files. Press OK to close the options window, then click Copy Now. Approx time: about 100 seconds for every GB.
  3. Boot off your external drive: Restart your computer and hold down the Option key. A volume select menu should come up within seconds. Click the arrow under your external drive to boot from it.
  4. Re-partition your original drive: Once you're booted into OSX again off your external drive, open up Disk Utility and select your original internal hard drive. Click on the Partition tab on the right side, and then click Options and select GUID. Click the Partition button to erase/repartition your original hard drive as GUID. Approximate Time: Less than five minutes.
  5. Re-copy your data back to your original drive: Open Superduper again. Two warning windows may pop up about Volumes not being found, but just click Cancel and ignore them. In the left Copy pulldown, select your external drive. In the right Copy pulldown, select your original internal drive. Under using, select Backup - all files. Click on the Options button, and then in the During Copy dropdown, select the first option that says Erase, then copy files. Press OK to close the options window, then click Copy Now. Approx time: about 100 seconds for every GB.
  6. Reboot and enjoy! Whew! So after all this work, you now have a GUID-partitioned internal hard drive that is essentially untouched from before, but now with a proper partition type than can be upgraded to Leopard or have bootcamp installed.
[robg adds: I haven't tested this one.]

Comments (6)


Mac OS X Hints
http://hints.macworld.com/article.php?story=2007102511133285