Hard Disk Partitioning Strategy

[Deputy-Dawg]

I hope to soon receive (like this week) a new C2D MacBook Pro. I will also be getting a 160 Gb firewire HD. I have an older PPC G4 that will continue to be an inuse machine. What I want to co is to create a bootable paritition for each machine on the external as an emergency recovery device. I understand that the two machines cannot be booted from the same system image (at least not with OSX 10.4.8). Indeed creating the two bootable images require just a bit of magic which I think I have sorted out.

My question is how to partition the disk. Several configurations come to mind. One would be to create two equal partitions, one for each OS image. Another would be to create one parition of about 10 Gb and leave the remainder of the disk in the other. Then install one image in the smaller partition and the other in the larger. Yet another possibility would be to create two small (say 10 Gb each) partions one for each of the OS images and leave the remainder of the HD as a scratch area and storage of backup files.

Finally throw in to mix that I will be using the external HD to provide a large scratch area for Photoshop.

How would you partion the drive and why?

 

[SmurfBoxMasta]

uumm.......Intel Macs & PPC macs require 2 very different disk formats and partition maps, neither of which is compatible with the other. And IIRC, there is currently no way to initialize a single drive with 2 different formats

 

[Deputy-Dawg]

uumm.......Intel Macs & PPC macs require 2 very different disk formats and partition maps, neither of which is compatible with the other. And IIRC, there is currently no way to initialize a single drive with 2 different formats

You are at least partially correct. The PPC uses and can only boot from an APM (Apple Partion Map) partitioned drive. The newer Intel Macs use GUID Partition Table (GPT) partitioned drives. For reasons that are not, to me at least, completely clear Apple built a test in the install disks distributed with the Intel Macs that prevents them from installing an OS image on an APM partitioned disk. But, the Intel Macs can boot from an image once installed on an APM partitioned disk. Indeed ironicaly the distribution DVDs are APM formatted. This is probably going to continue into the Panther release in that if it is not then Apple will have to make and distribute two different versions of Panther when it is released, one for the PPCs and another for the Intel Macs. The problem does not arise with the Tiger release because there is no need for a commercial release of Tiger that can install on an Intel Mac. Which is to say the commercial versions of Tiger cannot install on and Inel Mac.

So the problem is how to install a Intel bootable image on APM partitioned drive. Search the web this is discussed in several articles. Basically all you need to do is to install the OS on a GPT partitioned drive. Clone the image to a disk image, peserve the image, reformat the drive with APM partitioning and then clone the OS image back. This process is discussed in length in the following articles (among others)

http://db.tidbits.com/article/08405
http://rentzsch.com/tidbits/intelbasedMacBootIncompatibility
http://theappleblog.com/2006/02/28/booting-an-intel-mac-from-an-apm-partitioned-disk/
http://www.intellexcorp.com/4DMessages/5800/5824.html

So my question remains what is the best patitioning strategy.

 

[SmurfBoxMasta]

You are at least partially correct. The PPC uses and can only boot from an APM (Apple Partion Map) partitioned drive. The newer Intel Macs use GUID Partition Table (GPT) partitioned drives. For reasons that are not, to me at least, completely clear Apple built a test in the install disks distributed with the Intel Macs that prevents them from installing an OS image on an APM partitioned disk. But, the Intel Macs can boot from an image once installed on an APM partitioned disk. Indeed ironicaly the distribution DVDs are APM formatted. This is probably going to continue into the Panther release in that if it is not then Apple will have to make and distribute two different versions of Panther when it is released, one for the PPCs and another for the Intel Macs. The problem does not arise with the Tiger release because there is no need for a commercial release of Tiger that can install on an Intel Mac. Which is to say the commercial versions of Tiger cannot install on and Inel Mac.

So the problem is how to install a Intel bootable image on APM partitioned drive. Search the web this is discussed in several articles. Basically all you need to do is to install the OS on a GPT partitioned drive. Clone the image to a disk image, peserve the image, reformat the drive with APM partitioning and then clone the OS image back. This process is discussed in length in the following articles (among others)

http://db.tidbits.com/article/08405
http://rentzsch.com/tidbits/intelbasedMacBootIncompatibility
http://theappleblog.com/2006/02/28/booting-an-intel-mac-from-an-apm-partitioned-disk/
http://www.intellexcorp.com/4DMessages/5800/5824.html

So my question remains what is the best patitioning strategy.

OK, so assuming that the dbl format thing works (I have my doubts) then I see that you will need 3 partitions, 1 for ppc clone, 1 for Intel clone, and the 3rd for scratch disk.....

A typical PPC Tiger install runs between 2-10gb, and needs about 4-8GB free for swap file/VM. I dont know about the Intel version, but I would think it would be slightly larger overall.

So out of 160gb, you'd have ~120gb or so left for scratch use.... and thats more than enough in most normal cases