The Linux Bootdisk HOWTO

Tom Fawcett

        fawcett+BH@croftj.net
        

v4.0, April 2000

This document describes how to design and build your own boot/root diskettes for Linux. These disks can be used as rescue disks or to test new system components. You should be reasonably familiar with system administration tasks before attempting to build your own bootdisk. If you just want a rescue disk to have for emergencies, see Appendix A.1.


Table of Contents
Preface
Version notes
Yet to do
Feedback and credits
Distribution policy
Introduction
Bootdisks and the boot process
The boot process
Disk types
Building a root filesystem
Overview
Creating the filesystem
Populating the filesystem
Providing for PAM and NSS
Modules
Some final details
Wrapping it up
Choosing a kernel
Putting them together: Making the diskette(s)
Transferring the kernel with LILO
Transferring the kernel without LILO
Setting the ramdisk word
Transferring the root filesystem
Troubleshooting, or The Agony of Defeat
Miscellaneous topics
Reducing root filesystem size
Non-ramdisk root filesystems
Building a utility disk
How the pros do it
Frequently Asked Question (FAQ) list
Appendix A. Resources and pointers
Pre-made Bootdisks
Rescue packages
LILO -- the Linux loader
Linux FAQ and HOWTOs
Ramdisk usage
The Linux boot process
Appendix B. LILO boot error codes
Appendix C. Sample root filesystem listings
Appendix D. Sample utility disk directory listing

Preface

Important: This document may be outdated. If the date on the title page is more than six months ago, please check the Bootdisk-HOWTO homepage to see if a more recent version exists.

Although this document should be legible in its text form, it looks much better in Postscript, PDF or HTML forms because of the typographical conventions used.

Version notes

Graham Chapman wrote the original Bootdisk-HOWTO and he supported it through version 3.1. Tom Fawcett started as co-author around the time kernel v2 was introduced. He is the document's current maintainer.

This information is intended for Linux on the Intel platform. Much of this information may be applicable to Linux on other processors, but we have no first-hand experience or information about this. If you have experience with bootdisks on other platforms, please contact us.

Yet to do

Any volunteers?

  1. Describe (or link to another document that describes) how to create other bootable disk-like things, such as CDROMs, ZIP disks and LS110 disks.

  2. Describe how to deal with the huge libc.so shared libraries. The options are basically to get older, smaller libraries or to cut down existing libraries.

  3. Re-analyze distribution bootdisks and update the "How the Pros do it" section.

  4. Delete section that describes how to upgrade existing distribution bootdisks. This is usually more trouble than it's worth.

  5. Rewrite/streamline the Troubleshooting section.

Feedback and credits

I welcome any feedback, good or bad, on the content of this document. I/we have done our best to ensure that the instructions and information herein are accurate and reliable. Please let me know if you find errors or omissions. When writing, please indicate the version number of the document you're referencing.

We thank the many people who assisted with corrections and suggestions. Their contributions have made it far better than we could ever have done alone.

Send comments, corrections and questions to the author at the email address above. I don't mind trying to answer questions, but if you have a specific question about why your bootdisk doesn't work, please read the section called Troubleshooting, or The Agony of Defeat first.

Distribution policy

Copyright © 1995,1996,1997,1998,1999,2000 by Tom Fawcett and Graham Chapman. This document may be distributed under the terms set forth in the Linux Documentation Project License. Please contact the authors if you are unable to get the license.

This is free documentation. It is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.