3 Partition Trifecta: Mac OS X, Ubuntu, and Windows

I recently installed Mac OS X, Snow Leopard, Ubuntu Lucid Lynx, and Windows XP on my MacBook Pro in 3 separate partitions. This guide was very helpful.

Some of the things I learned are:

• Windows XP must be the last partition. Mac OS X is my first bootable partition and Ubuntu Lucid Lynx is my second.
• Boot camp will not recognize the Ubuntu partition. VMware Fusion running within the Mac OS X partition will not recognize the Ubuntu partition either. I hear you can hack some configuration settings to make it happen, but doing so will most likely corrupt the Ubuntu partition.
• The windows partition must contain a Master Boot Record (MBR) to be bootable. Be careful when installing Ubuntu after installing Mac OS X and Windows. The installation procedure likes to overwrite the MBR by default.

• No matter which OS you're running, all modern hard drives are limited to 4 primary (bootable) partitions. One of those partitions can be an extended partition and divided into as many logical partitions as you want though.
• Mac OS X uses the Globally Unique IDentifier (GUID) partition scheme to layout the partition table on the hard drive.
• The Mac OS X boot loader is located in /System/Library/CoreServices/boot.efi and runs as an Extensible Firmware Interface (EFI) application.
• EFI replaces the need for a dedicated boot loader (such as the BIOS firmware interface) and is responsible for kicking off other boot loader applications.

• In order to boot Ubuntu, GRUB (GNU GRand Unified Bootloader) must be installed in the Ubuntu partition. The Ubuntu installer will do this automatically.
• You can create a swap file in Ubuntu instead of specifying a partition for swap space during installation. You can create the file from within Ubuntu while the OS is active.

• GParted (Gnome Partition Editor) is a useful graphical tool for checking and resizing partitions from with Ubuntu.
• The Mac OS X partition can be non-destructively resized using the diskutil command-line tool; however, you must ensure that there is enough free space at the end of the Mac OS X partition if you wish to shrink it.
• iDefrag is an excellent commercial tool for compressing Mac OS X partition data and moving it towards the front of the partition. I had to start my MacBook Pro in target disk mode and attach it to my old PowerBook G4. I then ran iDefrag on my PowerBook and targeted my MacBook hard drive.

I use the rEFIt (re-fit) boot menu to choose which partition I boot into after my laptop starts up. As you can tell by its name, rEFIt takes advantage of the EFI capabilities of Intel Macs and other EFI-based machines. It's very slick and is installed directly from within Mac OS X while the OS is active.