What is disk partitioning?

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Summary: Partitions are ways of treating a single hard disk as if it were many. We'll look at why, how and when you might want to partition your hard drive.

What is disk partitioning and how do I use it?

Most folks actually never need to worry about disk partitioning. Your machine will have come pre-configured and that configuration is probably just fine for most uses.

There are some times when it might make sense to revisit how your hard disk is used at the lowest level, and that's where partitioning comes in.

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Partitioning is, very simply, a way to take a single physical hard disk and make it look like more than one disk by dividing up the space.

Really, that's all there is to it.

A great example is that many machines will come with a single hard disk divided into two partitions - one a very small one with "recovery" information on it, and another that represents the rest of the hard disk for day-to-day use. Sometimes the recovery partition is visible, other times not.

You can see what partitions are on your hard disk by using the Disk Management tool. Right click on My Computer, click on Manage and then click on Disk Management. Here's what it shows for my laptop:

You can see that my single 74.53 gigabyte hard drive is actually divided into three partitions: a tiny system configuration partition, a 2 gigabyte recovery partition which appears as drive D: on my machine, and then the balance of the drive as my drive C:.

So drives C: and D: look like separate disk drives, but in fact they reside in separate regions of the same physical hard disk.

Why Partition?

There are several different uses for partitioning. As we've seen it's one way manufacturers keep a separate location for recovery files that are less likely to be damaged inadvertently by normal use by being on a separate logical drive.

Other reasons include:

• Multiple OS's Many multi-boot managers are really just giving you a choice of which partition to boot from. So you could, for example, put Linux on one partition and Windows on another, and then choose which you want to run each time you reboot. Both partitions may or may not be visible to both operating systems depending on how they're formatted and the capabilities of the OS's.

• Performance Because partitioning happens at the physical level many people believe that if done properly you can arrange the data on your hard drive more effectively through the use of partitions. For example some folks create a separate partition to hold the system swap file. Personally I'm not convinced that partitioning actually helps much for these purposes.

• Backup and Recovery Many more people often partition their hard drives so as to separate "system" from "data", creating a separate partition for each. This could allow you to, for example, restore your system partition from a back up without affecting your data. Similarly, it could allow you to regularly or more simply backup your data only. This tends to be a tad error prone as many programs still insist on storing things on the system drive, but it can at times be a useful way to organize things.

How Should You Partition?

First realize that there are two ways to partition or re-partition your hard drive:

• Using Windows Disk Manager to create, delete, and modify partitions. In this case the partitions involved will be erased. All data thereon will be lost.

• Using a third party partition manager. There are several, and these tools will preserve the data on your partitions as you resize and otherwise adjust your system configuration.

The real question is should you?

In my opinion, unless you know enough to know exactly how it'll benefit you, you don't need to. And it's rare that partitioning actually buys you much more than simply keeping your hard disk organized using folders on a single partition. In fact, that's exactly how all my machines are configured: each hard disk is a single partition (unless, like my laptop, it came pre-configured some other way).

Now, I know a lot of people will disagree and indicate that they had some significant performance gains and that they have some wonderful backup and recovery success stories that they can attribute to having partitioned properly.

All quite possible.

But for the average user it's just not worth a lot of consideration.

Related:

• Ask Leo! - Can I make my C: partition bigger by taking space from D:?

• Ask Leo! - Why does my 31 gig drive have only 10gig of space after formatting?

• Ask Leo! - Why isn't there 80 gigabytes of free space on my empty 80 gigabyte drive?

Article 12061 | Posted December 4, 2007