Linux boot disks are useful in a number of situations, such as testing a
new kernel, recovering from a disk failure (anything from a lost boot
sector to a disk head crash), fixing a disabled system, or upgrading
critical system files safely (such as libc.so).
There are several ways of obtaining boot disks:
Use one from a distribution such as Slackware. This will at
least allow you to boot.
Use a rescue package to set up disks designed to be used
as rescue disks.
Learn what is required for each of the types of disk to operate,
then build your own.
Some people choose the last option so they can do it themselves. That way,
if something breaks, they can work out what to do to fix it. Plus it's a
great way to learn about how a Linux system works.
This document assumes some basic familiarity with Linux system
administration concepts. For example, you should know about
directories, filesystems and floppy diskettes. You should know how to
use mount and df. You should
know what /etc/passwd and
fstab files are for and what they look like. You
should know that most of the commands in this HOWTO should be run as
root.
Constructing a bootdisk from scratch can be complicated. If you
haven't read the Linux FAQ and related documents, such as the Linux
Installation HOWTO and the Linux Installation Guide, you should not be
trying to build boot diskettes. If you just need a working bootdisk
for emergencies, it is much easier to download a
prefabricated one. See Appendix A.1, below, for where to
find these.
Take our 
