The Linux Bootdisk-HOWTO

Part of the...

The Bootdisk-HOWTO describes how to design and build your own boot/root diskettes for Linux. These disks could be used as rescue disks or to test new system components. If you haven't read the Linux FAQ and related documents, such as the Linux Installation HOWTO and the Linux Install Guide, you should not be trying to build boot diskettes.

This document is intended for Linux kernel 2.0 and later on the Intel platform.

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.

 An on-line (HTML) version of the Bootdisk-HOWTO is available for quick reference.

Translations

• French: Disquettes d'amorce Linux
• Chinese
• Dutch: De Linux Bootdisk HOWTO
• Hungarian: Linux Indítólemez HOGYAN
• Japanese: (The Japanese Translation Project)
• Korean: (Korean Translations)
• Russian: (Russkiy yazik)

Problems

• Some people have been having trouble logging in after booting. They can't login (or if they do login, when they shutdown the system tells them ``You don't exist. Go away.'') This is usually caused by a problem with NSS. Check the versions of glibc and libnss_files.so. If you're using glibc-2.0, you need libnss_files.so.1. For glibc-2.1, used by recent RedHat and Mandrake distributions, you need libnss_files.so.2. These may be symlinks to the same file, but the correct one must exist.

• Some people have been having trouble with the dd command issuing a spurious error when given the seek= parameter. The error will look something like: dd: /dev/fd0: Invalid argumentThis is a bug in dd. This bug is fixed in the most recent fileutils (4.1). Check this page for the source download, or check updates for your distribution.

SEE ALSO: The Yard system, which builds bootdisks automatically from specifications. Yard automates many of the tedious details described in the Bootdisk-HOWTO.

Here is a perl script for dissecting bootdisks, from the Yard distribution. It's only a small hack, but it's useful for taking apart an unknown bootdisk image and reporting the options and root filesystem contents. I haven't tested it with initrd's yet.

  Need an emergency bootdisk?

You may not need to build one yourself. Here are some good pre-made rescue disks designed to help get you out of a jam.

• tomsrtbt is a single-disk boot/root disk based on kernel 2.0, with a large set of features and support programs. It supports IDE, SCSI, tape, network adaptors, PCMCIA and more. About 100 utility programs and tools are included for fixing and restoring disks. The package also includes scripts for disassembling and reconstructing the images so that new material can be added if necessary.
• rescue02 is a rescue disk based on kernel 1.3.84 with support for IDE and Adaptec 1542 and NCR53C7,8xx. It uses ELF binaries but it has enough commands so that it can be used on any system. There are modules that can be loaded after booting for all other SCSI cards. It probably won't work on systems with 4 mb of ram since it uses a 3 mb ram disk.

• resque_disk-2.0.22 is a full-featured boot/root disk based on kernel 2.0.22 with built-in support for IDE, many different SCSI controllers, and ELF/a.out. Also includes many modules and useful utilities for repairing and restoring a hard disk.

• The cramdisk images, based on the 2.0.23 kernel, are available for 4 meg and 8 meg machines. They include math emulation and networking (PPP and dialin script, NE2000, 3C509), or support for the parallel port ZIP drive. These diskette images will boot on a 386 with 4MB RAM. MSDOS support is included so you can download from the net to a DOS partition.

   

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