3.1. Overview of the Installation Process
First, just a note about re-installations. With Debian, a
circumstance that will require a complete re-installation of your
system is very rare; perhaps mechanical failure of the hard disk would
be the most common case.
Many common operating systems may require a complete installation to
be performed when critical failures take place or for upgrades to new
OS versions. Even if a completely new installation isn't required,
often the programs you use must be re-installed to operate properly in
the new OS.
Under Debian GNU/Linux, it is much more likely that your OS can be repaired
rather than replaced if things go wrong. Upgrades never require a
wholesale installation; you can always upgrade in-place. And the
programs are almost always compatible with successive OS releases. If
a new program version requires newer supporting software, the Debian
packaging system ensures that all the necessary software is
automatically identified and installed. The point is, much effort has
been put into avoiding the need for re-installation, so think of it as
your very last option. The installer is not
designed to re-install over an existing system.
Here's a road map for the steps you will take during the installation
Back up any existing data or documents on the hard disk where you
plan to install.
Gather information about your computer and any needed documentation,
before starting the installation.
Create partition-able space for Debian on your hard disk.
Locate and/or download the installer software and any specialized
driver files your machine requires (except Debian CD users).
Set up boot tapes/floppies/USB sticks, or place boot files (most Debian
CD users can boot from one of the CDs).
Boot the installation system.
Select installation language.
Activate the ethernet network connection, if available.
Create and mount the partitions on which Debian will be installed.
Watch the automatic download/install/setup of the
Install a boot loader
which can start up Debian GNU/Linux and/or your existing system.
Load the newly installed system for the first time, and make some
initial system settings.
Install additional software (tasks
and/or packages), at your discretion.
If you have problems during the installation, it helps to know which
packages are involved in which steps. Introducing the leading software
actors in this installation drama:
The installer software,
the primary concern of this manual. It detects hardware and loads
appropriate drivers, uses
dhcp-client to set up the
network connection, and runs
debootstrap to install
the base system packages. Many more actors play smaller parts in this process,
debian-installer has completed its task when
you load the new system for the first time.
Upon loading the new base system,
supervises adding users, setting a time zone (via
tzsetup), and setting up the
package installation system (using
apt-setup). It then
tasksel which can be used to select large
groups of related programs, and in turn can run
which allows you to choose individual software packages.
debian-installer finishes, before the
first system load, you have only a very basic command line driven
system. The graphical interface which displays windows on your monitor
will not be installed unless you select it during the final steps,
aptitude. It's optional because many Debian GNU/Linux
systems are servers which don't really have any need for a graphical
user interface to do their job.
Just be aware that the X system is completely separate from
debian-installer, and in fact is much more
complicated. Installation and trouble shooting of the X window
installation is not within the scope of this manual.