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Appendix E. An Introduction to Disk Partitions

/usr/local

, meaning that

/usr/local/man/whatis

would then reside on

/dev/hda7

rather

than

/dev/hda5

.

E.1.8. How Many Partitions?

At this point in the process of preparing to install Red Hat Linux, you will need to give some consid 

eration to the number and size of the partitions to be used by your new operating system. The question

of "how many partitions" continues to spark debate within the Linux community and, without any end

to the debate in sight, it is safe to say that there are probably as many partition layouts as there are

people debating the issue.

Keeping this in mind, we recommend that, unless you have a reason for doing otherwise, you should

at least create the following partitions:

A swap partition   Swap partitions are used to support virtual memory. In other words, data is

written to swap when there is not RAM to hold the data your system is processing. You must create

a swap partition to correctly use Red Hat Linux. The minimum size of your swap partition should

be equal to twice the amount of your computer's RAM or 32 MB, whichever is larger.

A

/boot

partition   The partition mounted on

/boot

contains the operating system kernel (which

allows your system to boot Red Hat Linux), along with a few other files used during the bootstrap

process.

Caution

Make sure you read Section E.1.9   the information there applies to the /boot partition!

Due to the limitations of most PC BIOSes, creating a small partition to hold these files is a good

idea. For most users, a 32 MB boot partition is sufficient.

A root partition (

/

)   The root partition is where

/

(the root directory) resides. In this partitioning

layout, all files (except those stored in

/boot

) reside on the root partition. Because of this, it is in

your best interest to maximize the size of your root partition. For example, a 1.2 GB root partition

may permit the equivalent of a workstation installation (with very little free space), while a 3.4 GB

root partition may let you install every package. Obviously, the more space you can give the root

partition, the better.

Specific recommendations concerning the proper size for various Red Hat Linux partitions can be

found in Section 1.5.

E.1.9. One Last Wrinkle: Using GRUB or LILO

GRUB and LILO are the most commonly used methods to boot Red Hat Linux on x86 based systems.

As operating system loaders, they operate "outside" of any operating system, using only the Basic I/O

System (or BIOS) built into the computer hardware itself. This section describes GRUB and LILO's

interactions with PC BIOSes and is specific to x86 compatible computers.

E.1.9.1. BIOS Related Limitations Impacting GRUB and LILO

GRUB and LILO are subject to some limitations imposed by the BIOS in most x86 based computers.

Specifically, most BIOSes cannot access more than two hard drives, and they cannot access any data

stored beyond cylinder 1023 of any drive. Note that some recent BIOSes do not have these limitations,

but this is by no means universal.

All the data GRUB and LILO need to access at boot time (including the Linux kernel) is located

in the

/boot

directory. If you follow the partition layout recommended above or are performing a

workstation or server install, the

/boot

directory will be in a small, separate partition. Otherwise, it