The Debian Administrator's Handbook

Debian CD-/DVD-ROMs can also be purchased; Raphaël Hertzog proposes some on his blog, where 10% of the profit is donated to the Debian Project, the remainder of which allows him to devote more time to Debian.

→ http://www.debian.org/CD/vendors/

→ http://raphaelhertzog.com/go/debian-cd/

4.1.2. Booting from a USB Key

Since recent computers are able to boot from USB devices, you can also install Debian from a USB key (this is nothing more than a small flash-memory disk). Be aware, however, that not all BIOSes are the same; some are able to boot from USB 2.0 devices, while others only work with USB 1.1. Besides, the USB key must have 512-bytes sectors, and this feature, while common, is never documented on the packaging of the keys you find for sale.

The installation manual explains how to create a USB key that contains the debian-installer. The procedure has been significantly simplified with Squeeze, since the ISO images for i386 and amd64 architectures are hybrid images that can boot from a CD-ROM as as well as from a USB key.

You must first identify the peripheral name of the USB key (ex: /dev/sdb); the simplest means to do this is to check the messages issued by the kernel using the dmesg command. Then you must copy the previously downloaded ISO image (for example debian-6.0.0-amd64-i386-netinst.iso) with the command cat debian-6.0.0-amd64-i386-netinst.iso >/dev/sdb; sync. This command requires administrator rights, since it directly accesses the USB key peripheral and blindly erases its content.

A more detailed explanation is available in the installation manual. Among other things, it describes an alternative method of preparing a USB key that is more complex, but that allows to customize the installer's default options (those set in the kernel command line).

→ http://www.debian.org/releases/stable/i386/ch04s03.html

4.1.3. Installing through Network Booting

Many BIOSes allow booting directly from the network by downloading the kernel to boot. This method (which has several names, such as PXE or TFTP boot) can be a life-saver if the computer does not have a CD-ROM reader, or if the BIOS can't boot from such media.

This installation method works in two steps. First, while booting the computer, the BIOS (or the network card) issues a BOOTP/DHCP request to automatically acquire an IP address. When a BOOTP or DHCP server returns a response, it includes a filename, as well as network settings. After having configured the network, the client computer then issues a TFPT (Trivial File Transfer Protocol) request for a file whose name was previously indicated. Once this file is acquired, it is executed as though it were a bootloader. This then launches the Debian installation program, which is executed as though it were running from the hard drive, a CD-ROM, or a USB key.

All the details of this method are available in the installation guide (“Preparing files for TFTP Net Booting” section).

→ http://www.debian.org/releases/stable/i386/ch05s01.html#boot-tftp

→ http://www.debian.org/releases/stable/i386/ch04s05.html

4.1.4. Other Installation Methods

When we have to deploy customized installations for a large number of computers, we generally choose an automated rather than a manual installation method. Depending on the situation and the complexity of the installations to be made, we can use FAI (Fully Automatic Installer, described in Section 12.3.1, “Fully Automatic Installer (FAI)”), or even a customized installation CD with preseeding (see Section 12.3.2, “Preseeding Debian-Installer”).

4.2. Installing, Step by Step

4.2.1. Booting and Starting the Installer

Once the BIOS has begun booting from the CD- or DVD-ROM, the Isolinux bootloader menu appears. At this stage, the Linux kernel is not yet loaded; this menu allows you to choose the kernel to boot and enter possible parameters to be transferred to it in the process.

For a standard installation, you only need to choose “Install” or “Graphical install” (with the arrows), then press the Enter key to initiate the remainder of the installation process. If the DVD-ROM is a “Multi-arch” disk (such as the one included with this book), and the machine has an Intel or AMD 64 bit processor, the menu options “64 bit install” and “64 bit graphical install” enable the installation of the 64 bit variant (amd64) instead of the default 32 bit variant (i386). In practice, the 64 bit version is only relevant on a server rather than a desktop workstation, since it will cause difficulties with the use of certain non-free software that are released only as binaries.

GOING FURTHER 32 or 64 bits?