View Full Version : Partition Schemes for Intel Mac

02-15-2007, 10:27 AM
I noticed that there are a few threads regarding this topic but I would just like it cleared up once and for all: which is the correct partition scheme (e.g. GUID Partition Table) to use when partitioning an external drive for booting with an Intel Mac?

Disk Utility states that the GUID Partition Table is for booting up Intel Macs but I have seen advice that the Apple Partition Map would also work but Disk Utility describes it for "[starting] up a PowerPC-based Macintosh computer or to use the disk as a non-startup disk with any Mac".

Does this mean what it seems to say: that you cannot boot an Intel Mac from a disk using Apple Partition Map and that instead you should use the GUID Partition Table scheme?

Thanks in advance,

-- Paul

02-15-2007, 10:42 AM
GUID is the "preferred" partitioning scheme for an Intel Mac. Intel Macs can, however, start up from Apple Partition Map partitioned drives.

So, use GUID unless you have a reason not to (e.g. you're sharing a drive between a Power PC and Intel Mac, have two partitions, and want each to be bootable for its corresponding Mac).

02-20-2007, 02:06 AM
I just finished a nice post on partitioning an external HD to use with OSX and XP in Bootcamp... and then it didn't post... so instead of rewritting everything... I'm just going to say.. to backup Xp and Intel Mac on the same hard drive... you want to avoid APM, use GUID... partition with Xp [EDIT: I Mean use Mac Disk Utility to create the partition scheme and choose GUID which will be compatible with XP for your backup... I would not use Xp's diskpart]... and create only three partitions.. [a fourth partition will be made which is the GPT aka GUID Partition Table.. but you can't see it using Disk Utility] one for a bootable osx copy [use Extended Journaled], one for an incremental osx backup [use Extended Journaled], and the last one an incremental backup of Xp... formated for MSDOS with Disk Utility.. and then when in Xp... take a peak at the External Harddrive while in DiskManager Snap In... and reformat this MSDOS aka FAT32 partition... into NTFS while in Xp... (with no partitioning... )... Use super easy SuperDuper for the Bootable OSX Copy and use Retro for the two Incremental Backups...[I'm using 2 versions of Retro.. Win.. and Mac... ] SuperDuper and Retro are a good match.. ease of use and clarity of explanation ... with confusing depth... which.. by the time you figure it out.. they'll have a Binary Version out... and the Permissions et issues.. are more critical with Bootable Copies anyway... which isn't an issue with SuperDuper...

Note that you'll want to disable MacDrive7 before using Retro (not sure about with SuperDuper).. I'm currently zeroing out my TB external hard drive after failing to disable MacDrive.. I guess if I had MacFuse up and running then I could have used Disk Utility to zero out a NTFS partition (?)

Nelson Weiderma
02-21-2007, 11:46 AM
So, use GUID unless you have a reason not to (e.g. you're sharing a drive between a Power PC and Intel Mac, have two partitions, and want each to be bootable for its corresponding Mac).

I'm trying to do exactly that -- have a bootable external shared drive between a Power PC and an Intel Mac.

As background, I have a LaCie 200GB firewire drive that was bootable with a single (APM) partition when my internal drive crashed (pre SuperDuper!). Now I have tried two partitions with various partitioning schemes (currently APM) and no matter what I name the Power PC partition or put in it (from the old backup), I get the question mark folder when I try to boot from the disk.

SuperDuper! is saving to the Intel Mac partition fine and I have been able to boot from it. The idea here is to have a backup both for the data and the computer, but if I can't boot from the external disk with the Power PC, the idea of a backup computer won't work.

Any ideas?

02-21-2007, 11:49 AM
I don't know why this would be, Nelson, unless the backup is for the wrong kind of Mac (intel/ppc), or doesn't have a true full backup on it...

Nelson Weiderma
02-22-2007, 10:26 AM
Figured it out. Turns out I needed to reinstall Tiger from disk on the Power PC. So now I am bootable from both Power PC and Intal Mac from the La Cie with APM partitions. Sweet!

02-23-2007, 01:06 AM
I have somewhat the opposite problem: I'm trying to backup two different Macs to an APM partitioned LaCie FW HD. The old G4 ppc desktop (OSX.3.9) backs up fine to volume 1, but when trying to back up the MacBookPro coreduo1 (OSX.4.8), volume 2 erases just fine, but will not begin to copy. Is my issue that I need to have both computers running Tiger? Thanks

02-23-2007, 11:14 AM
No... do you get an error? Have you tried restarting the Mac?

02-23-2007, 09:36 PM
Yes, I've tried restarting and get precisely the same error, which I've pasted below. I'm going to attach the entire log. Does it matter which computer or OS version did the partioning of the FW HD? Thanks for a great product and such prompt support!

| 10:44:02 AM | Error | 2007-02-22 10:44:02.173 SDCopy[524] NSExceptionHandler has recorded the following exception:
| 10:44:02 AM | Error | NSUncaughtSystemExceptionException -- Uncaught system exception: signal 11
| 10:44:02 AM | Error | Stack trace: 0xebebebeb

02-24-2007, 09:03 AM
This is a damaged migration of SD. If you download and install a fresh copy, it'll fix right up.

02-24-2007, 12:57 PM
Superduper looks super,
but there's a problem.
I'm running an XP virtual machine in Parallels,
and I'd love to do a backup of the contents.
I can map the XP C drive (oops, "connect to server") from OSX.
How can I get SD to see the mapped drive
so I can back it up?
(The entire XP C drive is a single 34GB file in OSX-- there's occasional but limited utility in backing up that file.)

02-24-2007, 01:28 PM
You can't, cybertubby -- personally, I just back up the image.

02-25-2007, 07:57 PM
Backup the image? ...

I've installed VMware's Fusion.. but haven't used it yet.. and have never used Parallels...

I noticed something about Fusion needing to create a 8GB area (I don't think it was MB... ) in NTFS... not sure if they mean virtualized NTFS or what... kinda freaks me out...

I want to install Vista to this...

And I have no idea what SuperDuper is going to do with this..

Will I be able to boot from an external HD... and run Vista? ?

02-26-2007, 10:08 AM
Yes: VMWare stores its disk on your HFS+ volume as a file. Remember not to back up while VMWare is running, and do recognize that every time you modify a file on the Windows drive, the whole 8GB (or whatever) will get copied.