1. Introduction

1.1 Why Build Boot Disks?

Linux boot disks are useful in a number of situations, such as:

• Testing a new kernel.
• Recovering from disk or system failure. Such a failure could be anything from a lost boot sector to a disk head crash.

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 various types of disk to operate, then build your own.

I originally chose the last option - learn how it works so that you can do it yourself. That way, if something breaks, you can work out what to do to fix it. Plus you learn a lot about how Linux works along the way.

Experienced Linux users may find little of use in this document. However users new to Linux system administration who wish to protect against root disk loss and other mishaps may find it useful.

A note on versions - this document has been updated to support the following packages and versions:

• Linux 2.0.6
• LILO 0.19

Copyright (c) Tom Fawcett and Graham Chapman 1995, 1996, 1997.

Permission is granted for this material to be freely used and distributed, provided the source is acknowledged. The copyright conditions are intended to be no more restrictive than version 2 of the GNU General Public License as published by the Free Software Foundation.

No warranty of any kind is provided. You use this material at your own risk.

1.2 Feedback and Credits

We welcome any feedback, good or bad, on the content of this document. Please let us know if you find any errors or omissions. Send comments, corrections and questions to Tom Fawcett (fawcett@nynexst.com) or Graham Chapman (grahamc@zeta.org.au).

We thank the following people for correcting errors and providing useful suggestions for improvement:

        Randolph Bentson
        Grant R. Bowman
        Scott Burkett
        Cameron Davidson
        Bruce Elliot
        Javier Ros Ganuza
        HARIGUCHI Youichi
        Duncan Hill
        Bjxrn-Helge Mevik
        Lincoln S. Peck
        Dwight Spencer
        Cameron Spitzer
        Johannes Stille

1.3 Change History

v.2.3, 4 April 1997. Changes in this version:

• Moved first FAQ question ("Why doesn't my disk boot?") into its own section ("Troubleshooting") and added Yard troubleshooting information to it.
• Made a few changes suggested by D.Hill and J.R.Ganuza.
• Added ref and label tags in various places.
• Moved scripts and resources to appendices.
• Added URLs for distributions' bootdisks plus mirrors.

v2.2, 1 September 1996. Changes in this version:

• Fix: set ramdisk word via rdev on /dev/fd0 instead of zImage.

v2.1, 18 August 1996. Changes in this version:

Summary: this was a major cleanup to reflect changes between kernel version 1.2 and 2.0. Specific changes are:

• Chg: replaced shell scripts and directory listings.
• Chg: removed most of the text of "oversize ramdisk" FAQ question.
• Fix: mkfs -i should have been mke2fs -i.
• Fix: missing parameter name in dd command to zero rootdisk device.
• Fix: remove accidental extra parameter from mke2fs command to create rootdisk filesystem.
• Chg: minor changes to reflect less reliance on the Bootkit utility.
• Chg: change section cross-references to refer to section title, not number (sometime I'll add hypertext links...)
• Add: use cpio as an alternate way of copying files.
• Add: tips for removing unnecessary device special files.
• Add: FAQ question - what to do if nothing happens at boot time.
• Add: various minor changes.

v2.0, 12 June 1996. Changes in this version:

• Add: additional author and maintainer, Tom Fawcett.
• Add: section 6.3, Ramdisk Usage.
• Add: section titled Advanced Bootdisk Creation, which describes how to take advantage of ramdisk changes in kernels 1.3.48+
• Chg: rewrite section on /lib directory.
• Chg: various minor tips on changed ramdisk usage.

Version history:

• v1.02, 25 June 1995 - minor changes.
• v1.01, 6 February 1995 - minor changes.
• v1.0, 2 January 1995 - first release in standard HOWTO layout.
• v0.10, 1 Novemer 1994 - original version, labelled "Draft".