Why would you want to run Linux on a Mac? There are probably a few good reasons -- learning about a different OS, using software that's not available on the Mac platform, or for a Linux class in school. While you can create a bootable partition on your Mac and boot Linux from it, I prefer to do things the lazy way. In this short how-to post, I'll demonstrate how I installed Ubuntu Linux 9.04, also known as "Jaunty Jackalope."
Step 1: Download and install VirtualBox
To get a free copy of Sun's excellent VirtualBox VM environment, point your browser to http://www.virtualbox.org/wiki/Downloads. Choose the link for Intel Macs (sorry, it doesn't run on those old PowerPC Macs), and click the download link. When the download is done, mount the disk image and follow the simple installation instructions. You'll end up with a VirtualBox icon in your Applications folder.
Step 2: Download the Ubuntu ISO
Visit http://www.ubuntu.com/getubuntu/download. The download page should recognize that you're browsing from a Mac and offer the Intel Mac ISO image. Choose a download host close to your geographical location from the pop-up menu, then click the Begin Download button to start transferring the file to your Mac. Choose to Save the ISO file rather than Open or mount it.
Step 3: Launch VirtualBox
From your Applications folder or Dock, launch VirtualBox. If you haven't launched it before, you'll be asked to register the application. In the other window that appears, you'll see something similar to this:
Step 4: Create a new virtual machine
See that New button in the screenshot above? Click on it. What's going to appear is the New Virtual Machine Wizard. When it appears, click the Next button and this dialog appears:
When you've chosen the OS and Version, click Next.
Step 5: Select the base memory for the virtual machine
You need to set a base amount of memory that can be used by the virtual machine (see below). I selected the recommended base amount of 384 MB, then clicked the Next button.
Step 6: Create a new hard disk
Don't worry, you're not really creating a new physical hard disk; like the Linux machine you're creating, it's virtual. This hard disk will take up space on your physical drive, so make sure that you have enough free space to create the hard disk and still have enough capacity to continue to store your documents. You can save the virtual disk on an external disk drive if you want to. To start the process of creating the new virtual disk, take the default settings that are listed on the dialog below:
After selecting the maximum amount of hard drive space you want, click Next, and then click Finish on the final screen to build your virtual hard disk. At this point, you're almost done. On the summary display that appears (see below), check the settings and then click Finish if you're ready to build your virtual Ubuntu Linux machine.
Step 7 -- Preparing to load Linux
VirtualBox now shows that you have one virtual machine called Ubuntu Linux. It's currently "powered off," but we'll change that soon. You want to make sure that you have your Ubuntu Linux DVD image ready to load. That's the Ubuntu ISO image we saved earlier.
Step 8 -- Loading Linux
At this point you're ready to rock and roll. You should be back at the VirtualBox list of virtual machines, with Ubuntu Linux on the launchpad ready to go:
Once you click OK, VirtualBox is going to run Ubuntu off of the virtual DVD. It looks something like this:
Step 9 -- Update Ubuntu
Once the installation is completed, you'll either be asked to log in with your password, or if you set the installer to log you in automatically, you'll be at the Ubuntu Linux desktop. Since your network connection is already set up, the next thing that will happen is that Ubuntu will check for updates. This is the Ubuntu equivalent of the Software Update in Mac OS X.
Step 10 -- Play!
Once the updates are done, it's time to play with your Ubuntu virtual machine. The user interface is somewhat different from that of Mac OS X, so you'll have to get used to it. You can read Ubuntu's built-in help files by clicking on the question mark icon in the menu bar.
While I will leave the task of learning Ubuntu Linux up to you, one thing I will point out is the Add/Remove Software item under the Applications menu. This is your portal to a large library of software, all of which you can download with a click or two. Think of this as the "App Store" for Linux.
You also have a full office suite installed on your virtual Linux machine. The word processor, spreadsheet, and presentation applications of OpenOffice are all pre-installed with Ubuntu, along with calendar and email functions.
While your Ubuntu Linux virtual machine won't replace your Mac or the applications on it, you can certainly learn a lot more about the Linux world and about virtual machines for free through this tutorial. Have fun!