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Convert a drive from Apple Partition Map to GUID Storage Devices
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
  • A blank external FireWire hard drive, size equal or larger than your current drive.
  • The free version of SuperDuper.
  • A bit of time! This took about four hours of processing for my 160gb drive on a 1.83ghz Core Duo Macbok.
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.]
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Convert a drive from Apple Partition Map to GUID | 5 comments | Create New Account
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Convert a drive from Apple Partition Map to GUID
Authored by: rawhead on Oct 30, '07 08:35:36AM
Well, not to be an attention whore, but I don't see how this hint is much different from the one I submitted

http://www.macosxhints.com/article.php?story=20071025070335493

Although I didn't get into the details about using the backup software (I used Carbon Copy Cloner instead of SuperDuper!).

Anyway, that's not why I'm posting this. I figured out a definitely quicker way of doing this whole process (only AFTER I'd done it pretty much the same way). This will work so long as you don't need to "Upgrade Install" but are fine just doing an "Archive and Install" (which I would suggest to anybody upgrading anyway).


1. Make a clone of your HDD to an external drive using your software of choice (CCC, SuperDuper, whatev).
2. Use your Leopard DVD to boot your Mac, partition using GUID, and go ahead and do a clean install of Leopard
3. Once installed, go into /Applications/Utilities/ and run Migration Assistant.
4. Use Migration Assistant to migrate your user data over from the external HDD with the system clone on it.

This will cut down on the time it takes to re-clone your internal HDD, which, for me and my 100GB of data, took HOURS.

---
All these moments will be lost in time
Like tears in rain.
Time to die.

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Convert a drive from Apple Partition Map to GUID
Authored by: Armen52 on Oct 30, '07 10:24:03AM

Not sure why any of this is a hint. You want to do something to the drive that generally requires blowing away its contents. Move it to another drive before you do that, then move it back.

What would be great is if we could find a way to change partition table formats without requiring those steps or ending up destroying the contents of a drive. That would have helped me this past weekend while trying to install Leopard.



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Convert a drive from Apple Partition Map to GUID
Authored by: mclbruce on Oct 30, '07 08:56:20AM

You don't need SuperDuper or Carbon Copy Cloner to do this. Apple's Disk Utility has a Restore command that will clone a disk.



[ Reply to This | # ]
Convert a drive from Apple Partition Map to GUID
Authored by: shavenyak on Oct 30, '07 12:57:29PM

If you're upgrading to Leopard anyway, wouldn't it be just as easy to backup your stuff, and repartition and format your drive with the Leopard install disk while doing a clean install? That way, you only need a big enough external drive to hold your data.

I'm wondering, though, why the heck Disk Utility apparently defaulted to APM in the first place, if the next release of the operating system was going to complain about installing on such disks.



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Convert a drive from Apple Partition Map to GUID
Authored by: otagi on Oct 31, '07 06:42:22AM

Another solution is to use the commercial software iPartition, which can change the partition type from APM to GUID without a reformat. For an external drive at least; I have not tested it with an internal boot disk.



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