Appendix E.

An Introduction to Disk Partitions

Disk partitions are a standard part of the personal computer landscape and have been for quite some

time. However, with many people purchasing computers featuring pre installed operating systems,

relatively few people understand how partitions work. This chapter attempts to explain the reasons

for and use of disk partitions so your Red Hat Linux installation will be as simple and painless as

possible.

If you are reasonably comfortable with disk partitions, you could skip ahead to Section E.1.4, for

more information on the process of freeing up disk space to prepare for a Red Hat Linux installation.

This section also discusses the partition naming scheme used by Linux systems, sharing disk space

with other operating systems, and related topics.

E.1. Hard Disk Basic Concepts

Hard disks perform a very simple function   they store data and reliably retrieve it on command.

When discussing issues such as disk partitioning, it is important to know a bit about the underlying

hardware. Unfortunately, it is easy to become bogged down in details. Therefore, we will use a simpli 

fied diagram of a disk drive to help explain what is really happening when a disk drive is partitioned.

Figure E 1, shows a brand new, unused disk drive.

Figure E 1. An Unused Disk Drive

Not much to look at, is it? But if we are talking about disk drives on a basic level, it will do. Say

that we would like to store some data on this drive. As things stand now, it will not work. There is

something we need to do first. . .

E.1.1. It is Not What You Write, it is How You Write It

Experienced computer users probably got this one on the first try. We need to format the drive. For 

matting (usually known as "making a file system") writes information to the drive, creating order out

of the empty space in an unformatted drive.