Partitioning Your Hard Drive

Evan Kleiman - 2002.01.21

Q. What's the deal with partitioning? What does it do?

A. Every computer has a hard drive these days; some have more than one. Those who own iMacs, PowerBooks, and iBooks, as well as many with Power Macs, will only have one internal hard drive.

But what if you want to have your single drive function as many separate hard drives?

There are many reasons partitioning your hard drive. Most people do it because they want to install a different OS on their system, such as Unix, Linux, or even OS X, while still have the convenience of OS 8 or 9 (or even lower) at their disposal.

Another good reason to partition is the ability to keep a live backup of your current operating system on another drive, just in case you're customizing your main OS and mess up (sort of like me) - then all you need to do is copy the clean System Folder from your back-up drive onto your main drive. Time saved: About 30-40 minutes, that is if you even know where your backup disks are.

People also do this because they want to get into video editing, don't need for a new hard drive, but want some separate space to store unfinished movies.

Now that you have some of the reasons for partitioning, how do you do it?

You should know that partitioning your drive reformats it, so you need to back-up all vital data before starting, since you will not be able to get it back once your drive has been partitioned and reformatted.

Okay, and now that we're done with the hard drive safety speech, we can begin the process.

First, you need to boot your computer off of something other than the hard drive you wish to partition - usually your bootup or restore CD, a floppy disk, a anything else that can boot the system. iMac, G3, and G4 users should make sure that they are using the "Software Restore" CDs instead of the "Software Install" disks, as only they will have the applications you will be needing. Otherwise you can use the "disk tools" floppy from System 7.5 for older Macs or the "OS 9.0 Installation" CD from newer Macs.

To boot from a CD, be sure it's in the drive and hold the "C" key on your keyboard during startup. Now you can either launch the Apple HD SC (used on older Macs) application or the Drive Setup application.

Now select your hard drive and click the initialize button. Some users will then see a "formatting options" button - click this and you should see a window with a large rectangle in it. This rectangle represents your hard drive. You can now divide your hard drive into as many partitions as you see fit (up to 8).

In the end, partitioning is a great way to distribute your free disk space to better organize your world or backup your life.

Next time we'll look at making one hard drive from many: the RAID array.

Further Reading

• Hard Drive Partitioning, Scott L. Barber, Online Tech Journal, August 1998