PowerPC/Intel boot drive conflicts

It's all very nice to worry about the different boot partition formats, but perhaps of greater worry is a lack, at this time, of a Intel Mac specific bootable version of Drive Genius, TechTool Pro, nor DiskWarrior. Of course this sort of thing has happened before, because of a mere Mac OS requirement of the very latest model Macs. You should have a external drive, properly formatted for your machine with a bootable OS for Drive Genius etc to be installed on, in order to repair or defragment your new Mac. Interesting to note that USB booting is now an option. Could you have an external FireWire drive, partitioned as GPT and APM with appropriate Mac OS 10.4.4 on each as a form of universal boot drive, with the ever popular option key at startup choosing the correct volume/partition?

- Bradley Dichter
Technical Advisor for the Long Island Macintosh Users Group

Dennis Wurster said:

>[No idea on booting an Intel iMac from USB, but you can't boot PowerPC
>Macs from USB, and I'd expect that you'd need to reformat the iPod if it
>were possible. Perhaps someone with one can chime in on USB-booting of
>Intel-based Macs. -Adam]
>
><http://db.tidbits.com/getbits.acgi?tbart=08405>


Actually, I've heard from folks who claim that they have been able to
boot their PowerPC Mac from a USB drive under OS 9, and some Apple
KnowledgeBase articles allude to this capability:

http://docs.info.apple.com/article.html?artnum=58430

However, OS X itself doesn't support USB booting, according to Apple:

http://docs.info.apple.com/article.html?artnum=106474

I haven't heard anything about this changing with the introduction of the
MacTel machines and/or OS X 10.4.4.



Randy B. Singer
Co-Author of: The Macintosh Bible (4th, 5th and 6th editions)

Routine OS X Maintenance and Generic Troubleshooting
http://www.macattorney.com/ts.html

 

At 7:16 AM -0800 2/2/06, Dennis Wurster wrote:
>I've used my 3G iPod to boot many modern Macs via FireWire. It's
>great for having a 'rescue disk' of utilities and such.
>
>I want to get a 5G (video) iPod, but those only support USB.
>
>Can I boot an Intel-powered Mac from a USB device like the iPod?

From what I've read, the Intel Macs won't boot with the regular Apple partition map, they need the new GUID partition table. However, the iPod won't boot with a GUID partition table. So I don't think you'll be able to boot your Intel Mac from an iPod.

http://en.wikipedia.org/wiki/GUID_Partition_Table
--

David


The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

 

--On February 2, 2006 1:23:59 PM -0800 "Randy B. Singer"
<randymacattorney.com> wrote:

> Actually, I've heard from folks who claim that they have been able to
> boot their PowerPC Mac from a USB drive under OS 9, and some Apple
> KnowledgeBase articles allude to this capability:

I've booted an original Tangerine iBook from USB into OS 9. I was never
able to boot my PowerBook G4 from USB but I can't remember if I tried with
OS 9. I thought it was a firmware thing rather than an OS thing.


 

The newly-shipping Intel iMac boots from a USB 2.0 drive as well as from a FireWire drive. I've done it.

And yes, holding the Option key down at startup allows you to choose the startup disk from a prettier-than-ever on-screen menu.

[Alert! Vendor promotion follows! -Andrew]

You can use Synchronize! Pro X 5.0 www.qdea.com to make a "Bootable System Backup" to the USB or FireWire drive.

If the drive is erased using the default "Apple Partition Scheme", and you have two partitions, you can make a "Bootable System Backup" from a PPC Mac to another partition, and start up PPC and Intel Macs from the appropriate partition on the same hard disk.

Hugh Sontag - Qdea Technical Support

Hugh Sontag wrote:

If the drive is erased using the default "Apple Partition Scheme", and you have two partitions, you can make a "Bootable System Backup" from a PPC Mac to another partition, and start up PPC and Intel Macs from the appropriate partition on the same hard disk.

If I understand you correctly, you're saying that an external FireWire hard drive, partitioned using the Apple Partition Scheme (not GPT) into 2 partitions, one with a PPC version of OS X and the other with the Intel version of OS X, will then be able to successfully boot both PPC and Intel Macs. This has not been my experience, nor the experience of others who've posted about this subject on the web.

The problem, as I understood it, was this: the Open Firmware of PPC Macs does not recognize an external drive partitioned using GPT as a valid startup volume; and the EFI of Intel Macs does not recognize an external drive partitioned using APS as a valid startup volume. Since, due to technical issues, there's no way to partition a drive using elements of or a hybrid of both partition schemes (it's one or the other), there's currently no way to create an external drive that will boot both PPC and Intel Macs.

Does Synchronize! Pro X 5.0 have any special features that allow one to work around these limitations? For those of us who will have to support both older and newer Macs for some time to come, and would prefer to carry one instead of two portable boot drives, this would be something worth checking out.

Chris

I came across this thread while trying to find a solution to use my firewire drive on both my Intel macs and PPC macs I found the solution here: http://eshop.macsales.com/Reviews/Framework.cfm?page=Tips/dualboot/dualboot.html Its a well written step by step process, not quite the easy fix I had hoped for but it does work, you could also use this process to upgrade a PPC drive to a intel drive then just delete the PPC boot partition if you don't need it anymore.

-frequencydip http://maclenders.com