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 producing 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. Once I understood how it all worked, then I changed to using the Bootkit rescue package to maintain my boot disks.

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 1.2.0
• LILO 0.15

Copyright (c) Graham Chapman 1995.

Permission is granted for this material to be freely used and distributed, provided the source is acknowledged. No warranty of any kind is provided. You use this material at your own risk.

1.2 Feedback and Credits

I welcome any feedback, good or bad, on the content of this document. Please let me know if you find any errors or omissions.

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

        Randolph Bentson
        Grant R. Bowman
        Scott Burkett
        Bruce Elliot
        HARIGUCHI Youichi
        Bjxrn-Helge Mevik
        Dwight Spencer
        Cameron Spitzer
        Johannes Stille

1.3 Change History

v1.02, 25 June 1995

• Add: FAQ question on oversize ramdisk filesystems.
• Add: if using mkfs, use the -i option.
• Add: can use cp as well as dd to copy to raw disk.
• Chg: correct explanation of /dev/fd0 vs /dev/fd0H1440.
• Chg: use "zImage" terminology to conform to standard usage.
• Add: mke2fs -m 0 will provide more usable disk space.
• Add: re-run LILO if the kernel has changed.
• Add: move rescue packages to new section under "References".
• Add: new rescue packages Bootkit and CatRescue.
• Add: FAQ question on cannot execute errors.
• Add: shell scripts are samples only - I now use Bootkit.
• Chg: stop using < and > in command examples - too confusing.
• Chg: sample directory listings are now of diskettes, not model.
• Chg: use more consistent terminology with ramdisks.

• Fix: DO NOT cp kernel_filename /dev/fd0 - this will overwrite any file system on the diskette.
• Fix: Put LILO boot.b and map files on target disk.
• Add: -dp flags to cp commands to avoid problems.
• Chg: restructure to try to improve readability.
• Add: can now use ext2 filesystem on root diskettes.
• Chg: can now separate boot and root diskettes.
• Add: credits section in Introduction.
• Add: FAQ.

v1.0, 2 January 1995

• Converted to conform to HOWTO documentation standards.
• Added new section - Change History.
• Various minor corrections.

v0.10, 1 November 1994 Original version, labelled "draft".