The Debian Administrator's Handbook

To use Debian, you need to install it on a computer; this task is taken care of by the debian-installer program. A proper installation involves many operations. This chapter reviews them in their chronological order.

BACK TO BASICS A catch-up course in the appendices

Installing a computer is always simpler when you are familiar with the way it works. If you are not, make a quick detour to Appendix B, Short Remedial Course before reading this chapter.

The installer for Squeeze is based on debian-installer. Its modular design enables it to work in various scenarios and allows it to evolve and adapt to changes. Despite the limitations implied by the need to support a large number of architectures, this installer is very accessible to beginners, since it assists users at each stage of the process. Automatic hardware detection, guided partitioning, and graphical user interfaces have solved most of the problems that newbies used to face.

Installation requires 56 MB of RAM (Random Access Memory) and at least 650 MB of hard drive space. All Falcot computers meet these criteria. Note, however, that these figures apply to the installation of a very limited system without a graphical desktop. A minimum of 512 MB of RAM and 5 GB of hard drive space are really recommended for a basic office desktop workstation.

BEWARE Upgrading from Lenny

If you already have Debian Lenny installed on your computer, this chapter is not for you! Unlike other distributions, Debian allows updating a system from one version to the next without having to reinstall the system. Reinstalling, in addition to being unnecessary, could even be dangerous, since it could remove already installed programs.

The upgrade process will be described in Section 6.6, “Upgrading from One Stable Distribution to the Next”.

4.1. Installation Methods

A Debian system can be installed from several types of media, as long as the BIOS of the machine allows it. You can for instance boot with a CD-ROM, a USB key, or even through a network.

BACK TO BASICS BIOS, the hardware/software interface

BIOS (which stands for Basic Input/Output System) is a software that is included in the motherboard (the electronic board connecting all peripherals) and executed when the computer is booted, in order to load an operating system (via an adapted bootloader). It stays in the background to provide an interface between the hardware and the software (in our case, the Linux kernel).

4.1.1. Installing from a CD-ROM/DVD-ROM

The most widely used installation media is CD-ROM (or DVD-ROM, which behaves exactly the same way): the computer is booted from this media, and the installation program takes over.

Various CD-ROMs have different purposes: netinst (network installation) contains the installer and the base Debian system; all other programs are then downloaded. Its “image”, that is the ISO-9660 filesystem that contains the exact contents of the disk, only takes up about 150 MB. Then we have the businesscard or bizcard CD-ROM, which only provides the installer, and which requires all the Debian packages (including the base system) to be downloaded. Since its image only takes up 35 MB, it can be burnt on a “business card” type CD-ROM, from which it takes its name. Finally, the complete set offers all packages and allows for installation on a computer that has no Internet access; it requires around 50 CD-ROMs (or eight DVD-ROMs, or two Blu-ray disks). But the programs are divided among the disks according to their popularity and importance; the first three disks will be sufficient for most installations, since they contain the most used software.

TIP Multi-architecture disks

Most installation CD- and DVD-ROMs work only with a specific hardware architecture. If you wish to download the complete images, you must take care to choose those which work on the hardware of the computer on which you wish to install them.

Some CD/DVD-ROM images can work on several architectures. We thus have a netinst CD-ROM image for the i386 and amd64 architectures. There is also a DVD-ROM image that contains the installer and a selection of binary packages for i386 and amd64, as well as the corresponding source packages.

To acquire Debian CD-ROM images, you may of course download them and burn them to disk. You may also purchase them, and, thus, provide the project with a little financial support. Check the website to see the list of CD-ROM image vendors and download sites.

→ http://www.debian.org/CD/index.html

IN PRACTICE Debian on CD-ROM