Thursday, January 28, 2010

How to Dual boot Mac OSX 10.6 Snow Leopard and Mac OSX 10.5.8 Leopard

I work for a small software company that one day decided it needed to support Safari 4 for Snow Leopard and Leopard. We had an older Mac Mini with an Intel Core Solo that I had upgraded to Mac OSX 10.5.8 Leopard from Mac OSX 10.4. Thanks to Apple's tactics of only allowing retail copies of their software (not OEM versions) to be used on different machines; we had to purchase the Mac OSX Leopard discs. During our search for solutions to this dual Mac OSX problem it became apparent that running two different versions of Mac OSX was not something Apple wanted people to do. With no virtualization support, there is no way to run Mac OSX Snow Leopard on the PC and no way to run Mac OSX on Mac OSX... They are a hardware company after all!

We decided to purchase a new 27" iMac and use the video in to connect our Mac Mini so we could consolidate some of our hardware and still be able to toggle between Mac OSX Snow Leopard and Leopard. After much hassle and some searching on Google we found out that you can only hook the 27" iMac up to another computer that uses the Mini DisplayPort, using a special cable. This would have been great information for the Geniuses at the Apple Store to know. This also ruled out hooking it up to the Mac Mini which only has a DVI port.

The next logical thought, since we couldn't hook up the Mac Mini and 27" iMac, was to dual boot Snow Leopard and Leopard using partitions. I created a partition using Disc Utility, then booted to the Mac OSX Leopard retail discs, selected the disc on the boot menu and watched as the system would hang. Somehow the installers check to see if the machine is newer than it is and then the install stops. All the user sees is a blank screen. In the end I found a rather easy way to dual boot between Mac OSX 10.6 Snow Leopard and Mac OSX 10.5.8 Leopard using a software program called SuperDuper! 2.6.2. I basically cloned my Mac Mini that had Leopard installed and then restored it onto a partition on the iMac. Note: you have to purchase the full version for this to work:

  1. Using Disc Utility on your Snow Leopard computer, create a Journal Extended partition
  2. On your Leopard computer, download and install SuperDuper! 2.6.2
  3. Register and pay for the full version (otherwise you won't be able to use the Sandbox mode)
  4. Copy your Leopard Macintosh HD to a Disk Image
  5. When prompted:
    1. Specify an image name on your external Hard Drive
    2. Use Read Only mode – it's the fastest
  6. Select using Sandbox – shared users
  7. Click Copy Now
  8. When the copy is complete you will now have a clone of your Leopard Hard Drive
  9. Install SuperDuper! On your Snow Leopard computer
  10. Copy your image to your new partition
  11. Click Copy Now
  12. When the copy is complete you will now be able to dual boot Snow Leopard and Leopard
  13. You can check to see if it worked by going into preferences in Snow Leopard and making sure both Startup discs are there.

This cloning process worked fine on the first try, it just took a few hours. When I booted into the Leopard partition for the first time on the iMac, I renamed the hard drive so I could distinguish it from the other drives. When SuperDuper! copies over the partition both drives will be called Macintosh HD. Don't rename the Leopard partition in Snow Leopard, this will cause problems. Also you don't rename the Snow Leopard partition at all otherwise the sandbox won't be able to share user information and you'll be unable to login. So far, the only problem that we've noticed running Leopard on the iMac is the airport card isn't recognized. This isn't a problem if you use the Ethernet connection but it could potentially be annoying.

Hopefully when Apple comes out with the successor to Snow Leopard we will be able to use SuperDuper! to create a new sandbox clone of Snow Leopard and then be able to run all 3 variations of OSX. You've got to hand it to Apple on computer designs; they're the best. The problem is they are the worst when it comes anything else – like software and compatibility.


Notes – New Info and Recaps:

  • We eventually found that Snow Leopard and Leopard deal with web security certificates differently regardless of the version of Safari.
  • The OEM discs that come with your product can only be used on the same type of machine. You need retail copies to upgrade non-exact replica machines. I.E you can't use the iMac's snow Leopard discs to upgrade a Mac Mini.
  • The 27" iMac only does video in with the mini Display Port using the Mini DisplayPort to Mini DisplayPort cable by Belkin and can't be daisy chained or converted.
  • The 27" iMac can't boot to older Mac OSX discs like Leopard, it just hangs.
  • The SuperDuper! sandbox partition of Mac OSX Leopard seemed to work fine on the 27" iMac except our wireless / airport card wasn't recognized. That didn't matter for us since we were hardwired.
  • We bootcamped the 27" iMac and put Windows 7 Enterprise on it so we could use it for more than a Mac testing box. Apparently Windows doesn't have the built in drivers for this version of the iMac screen and so as soon as you get to a certain point in the installation process, the screen goes blank. Before you attempt to install Windows 7, do a quick Google search, find the drivers and put them on a USB drive. When the installation starts you can press a key (I can't remember the exact one) to include the new screen drivers and avoid the problem from the start!


Chris Kenst said...

Here's the article on the iMac and Windows 7 problems:

Anonymous said...

Hey, I'm just wondering what type of CPU is your iMac using? Core 2 Duo or Core i series? I have a new Core i5 Macbook Pro and it won't boot using your suggested approach. I'm suspecting if 10.5 doesn't support the CPU at all.
However, it works on other Macbook Pro (Core 2 Duo CPU, Mid 2009 model), every app works but the weird thing is I can't change any thing on OS X like creating folder or writing anything to the disk. Should I use the Read/Write Sparse Bundle image type instead of Read-only Disk Image type?

Chris Kenst said...

The CPU is a Core 2 Duo. I'm not sure why you wouldn't be able to write anything to the disk. Did you use SuperDuper?

Anonymous said...

The write issue is fixed once I create a new user and use it to login. However, I still can't boot my Core i5 Macbook Pro from the 10.5 partition. I think 10.5 simply doesn't support this CPU or motherboard.

Chris Kenst said...

It's possible, OS X Leopard 10.5 is a little old. I think it came out in 2007. OS X Snow Leopard 10.6 is when Apple began committing fully to Intel based processors.

Chris Kenst said...

I wonder if you could use SuperDuper to clone Mac OS X Snow Leopard to install it in a virtual environment using VMware or VirtualBox. Then you could have a somewhat powerful version of Mac OSX Snow Leopard on Windows!

zeph said...

Hi, interesting read. I face a similar challenge:

I want to clone my old iMac on the 4th drive in my new MacPro. I have the full version of Superduper on the iMac.

I want to have a dual boot on my new machine with the old system running from its own drive.

I have seen that superduper can make bootable copies from a backup, but someone warned me that the iMac clone may not boot on the MacPro because of the hardware drivers?