2 Different Partition Map Scheme's for one external hard drive

You'll need to use separate drives.

It's possible to have multiple partitions on an external drive, when starting up your Mac hold down the 'option' key and it will list all available Boot partitions. Many users have a dual-boot Windows/OSX setup on their internal drive too.

Also, you can use emulation such as Parallels or VMWare and install Ubuntu, Windows 7, RedHat etc. and run multiple OS's alongside one another (Parallels is my favourite)

And this drive is currently not partitioned I take it ?

You need to make a backup of the data on the drive then partition it, the first partition must be set under Disc Utility / Partition / Options as Mac GUI Bootable so it installs the drivers, then install Tiger onto the first partition and move your current data back onto the second one.

You will then be able to Boot Tiger on the older PowerBook by holding down 'option' at start up, if you just have it connected to the MacBook Pro and start up normally then it will appear as two volumes on your Desktop, the Tiger Boot Volume and your Data Volume.

iVmichael: Please help me understand this too, if I was mistaken above. My understanding is that booting a PowerPC Mac requires the drive to be partitioned using the Apple Partition Map scheme, and booting an Intel Mac requires it to be partitioned using the GUID partion scheme. I don't see how any drive can be partitioned using both schemes.

Hi all,

have a look at this Apple document: http://support.apple.com/kb/HT2595

"Intel-based Macs computers can boot Mac OS X from APM disks, but when run on an Intel-based Mac, the installer for Mac OS X only allows the system to be installed on GUID Partition Table disks. Otherwise APM disks can be used normally.

PowerPC-based systems can only boot Mac OS from APM disks, but otherwise can use GUID Partition Table disks normally."

(courtesy of http://en.wikipedia.org/wiki/ApplePartitionMap )

Regards

Stefan

Hi eww: I read the post as being "Boot Tiger from a Volume" and "Use a Volume as backup for Intel Mac files" not that two different (and conflicting) Boot Volumes were wanted ... as you say you can't have both flavours in one.

Very interesting, stefan — thanks for this information, which is news to me.

I wonder WHY the Installer is designed to accept only a GUID-partitioned drive as a usable volume for installation when running on an Intel Mac, if an APM-partitioned drive would actually work to boot the Intel machine? Seems like an odd decision by Apple.

I have not seen it mentioned in this thread but I think a pre Intel MAC cannot be booted via USB but needs a Firewire external drive connection. Something to consider