Installing &debian; from a Unix/Linux System
This section explains how to install &debian; from an existing
Unix or Linux system, without using the menu-driven installer as
explained in the rest of the manual. This cross-install
HOWTO has been requested by users switching to &debian; from
Red Hat, Mandrake, and SUSE. In this section some familiarity with
entering *nix commands and navigating the file system is assumed. In
this section, $ symbolizes a command to be entered in
the user's current system, while # refers to a
command entered in the Debian chroot.
Once you've got the new Debian system configured to your preference,
you can migrate your existing user data (if any) to it, and keep on
rolling. This is therefore a zero downtime
&debian;
install. It's also a clever way for dealing with hardware that
otherwise doesn't play friendly with various boot or installation
media.
Getting Started
With your current *nix partitioning tools, repartition the hard
drive as needed, creating at least one filesystem plus swap. You
need around 350MB of space available for a console only install,
or about 1GB if you plan to install X (more if you intend to
install desktop environments like GNOME or KDE).
Next, create file systems on the partitions. For example, to create an
ext3 file system on partition /dev/hda6 (that's
our example root partition):
# mke2fs -j /dev/hda6
To create an ext2 file system instead, omit -j.
Initialize and activate swap (substitute the partition number for
your intended Debian swap partition):
# mkswap /dev/hda5
# sync; sync; sync
# swapon /dev/hda5
Mount one partition as /mnt/debinst (the
installation point, to be the root (/) filesystem
on your new system). The mount point name is strictly arbitrary, it is
referenced later below.
# mkdir /mnt/debinst
# mount /dev/hda6 /mnt/debinst
If you want to have parts of the filesystem (e.g. /usr) mounted on
separate partitions, you will need to create and mount these directories
manually before proceding with the next stage.
Install debootstrap
The utility used by the Debian installer, and recognized as the
official way to install a Debian base system, is
debootstrap. It uses wget and
ar, but otherwise depends only on
/bin/sh and basic Unix/Linux tools
These include the GNU core utilities and commands like sed, grep, tar and gzip.
. Install wget and
ar if they aren't already on your current system,
then download and install debootstrap.
Or, you can use the following procedure to install it
manually. Make a work folder for extracting the .deb into:
# mkdir work
# cd work
The debootstrap binary is located in the Debian
archive (be sure to select the proper file for your
architecture). Download the debootstrap .deb from
the
pool, copy the package to the work folder, and extract the
files from it. You will need to have root privileges to install
the files.
# ar -x debootstrap_0.X.X_all.deb
# cd /
# zcat /full-path-to-work/work/data.tar.gz | tar xv
Run debootstrap
debootstrap can download the needed files directly
from the archive when you run it. You can substitute any Debian
archive mirror for http.us.debian.org/debian in
the command example below, preferably a mirror close to you
network-wise. Mirrors are listed at
.
If you have a &releasename; &debian; CD mounted at
/cdrom, you could substitute a file URL instead
of the http URL: file:/cdrom/debian/
Substitute one of the following for ARCH
in the debootstrap command:
alpha,
amd64,
arm,
hppa,
i386,
ia64,
m68k,
mips,
mipsel,
powerpc,
s390, or
sparc.
# /usr/sbin/debootstrap --arch ARCH &releasename; \
/mnt/debinst http://ftp.us.debian.org/debian
Configure The Base System
Now you've got a real Debian system, though rather lean, on disk.
chroot into it:
# LANG=C chroot /mnt/debinst /bin/bash
After chrooting you may need to set the terminal definition to be
compatible with the Debian base system, for example:
# export TERM=xterm-color
Mount Partitions
You need to create /etc/fstab.
# editor /etc/fstab
Here is a sample you can modify to suit:
# /etc/fstab: static file system information.
#
# file system mount point type options dump pass
/dev/XXX / ext3 defaults 0 1
/dev/XXX /boot ext3 ro,nosuid,nodev 0 2
/dev/XXX none swap sw 0 0
proc /proc proc defaults 0 0
/dev/fd0 /media/floppy auto noauto,rw,sync,user,exec 0 0
/dev/cdrom /media/cdrom iso9660 noauto,ro,user,exec 0 0
/dev/XXX /tmp ext3 rw,nosuid,nodev 0 2
/dev/XXX /var ext3 rw,nosuid,nodev 0 2
/dev/XXX /usr ext3 rw,nodev 0 2
/dev/XXX /home ext3 rw,nosuid,nodev 0 2
Use mount -a to mount all the file systems you
have specified in your /etc/fstab, or, to mount
file systems individually, use:
# mount /path # e.g.: mount /usr
Current Debian systems have mountpoints for removable media under
/media, but keep compatibility symlinks in
/. Create these as as needed, for example:
# cd /media
# mkdir cdrom0
# ln -s cdrom0 cdrom
# cd /
# ln -s media/cdrom
You can mount the proc file system multiple times and to arbitrary
locations, though /proc is customary. If you didn't use
mount -a, be sure to mount proc before continuing:
# mount -t proc proc /proc
The command ls /proc should now show a non-empty
directory. Should this fail, you may be able to mount proc from outside
the chroot:
# mount -t proc proc /mnt/debinst/proc
Setting Timezone
An option in the file /etc/default/rcS determines
whether the system will interpret the hardware clock as being set to UTC
or local time. The following command allow you to set that and choose
your timezone.
# editor /etc/default/rcS
# tzconfig
Configure Networking
To configure networking, edit
/etc/network/interfaces,
/etc/resolv.conf,
/etc/hostname and
/etc/hosts.
# editor /etc/network/interfaces
Here are some simple examples from
/usr/share/doc/ifupdown/examples:
######################################################################
# /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)
# See the interfaces(5) manpage for information on what options are
# available.
######################################################################
# We always want the loopback interface.
#
auto lo
iface lo inet loopback
# To use dhcp:
#
# auto eth0
# iface eth0 inet dhcp
# An example static IP setup: (broadcast and gateway are optional)
#
# auto eth0
# iface eth0 inet static
# address 192.168.0.42
# network 192.168.0.0
# netmask 255.255.255.0
# broadcast 192.168.0.255
# gateway 192.168.0.1
Enter your nameserver(s) and search directives in
/etc/resolv.conf:
# editor /etc/resolv.conf
A simple example /etc/resolv.conf:
search hqdom.local
nameserver 10.1.1.36
nameserver 192.168.9.100
Enter your system's host name (2 to 63 characters):
# echo DebianHostName > /etc/hostname
And a basic /etc/hosts with IPv6 support:
127.0.0.1 localhost DebianHostName
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
If you have multiple network cards, you should arrange the names of
driver modules in the /etc/modules file into the
desired order. Then during boot, each card will be associated with the
interface name (eth0, eth1, etc.) that you expect.
Configure Apt
Debootstrap will have created a very basic
/etc/apt/sources.list that will allow installing
additional packages. However, you may want to add some additional sources,
for example for source packages and security updates:
deb-src http://ftp.us.debian.org/debian etch main
deb http://security.debian.org/ etch/updates main
deb-src http://security.debian.org/ etch/updates main
Make sure to run aptitude update after you have
made changes to the sources list.
Configure Locales and Keyboard
To configure your locale settings to use a language other than
English, install the locales support package
and configure it. Currently the use of UTF-8 locales is recommended.
# aptitude install locales
# dpkg-reconfigure locales
To configure your keyboard (if needed):
# aptitude install console-data
# dpkg-reconfigure console-data
Note that the keyboard cannot be set while in the chroot, but will be
configured for the next reboot.
Install a Kernel
If you intend to boot this system, you probably want a Linux kernel
and a boot loader. Identify available pre-packaged kernels with:
# apt-cache search linux-image
If you intend to use a pre-packaged kernel, you may want to create the
configuration file /etc/kernel-img.conf before you
do so. Here's an example file:
# Kernel image management overrides
# See kernel-img.conf(5) for details
do_symlinks = yes
relative_links = yes
do_bootloader = yes
do_bootfloppy = no
do_initrd = yes
link_in_boot = no
For detailed information about this file and the various options, consult
its man page which will be available after installing the
kernel-package package. We recommend that you check
that the values are appropriate for your system.
Then install the kernel package of your choice using its package name.
# aptitude install linux-image-&kernelversion;-arch-etc
If you did not create a /etc/kernel-img.conf before
installing a pre-packaged kernel, you may be asked some questions during
its installation that refer to it.
Set up the Boot Loader
To make your &debian; system bootable, set up your boot loader to load
the installed kernel with your new root partition. Note that
debootstrap does not install a boot loader, though you
can use aptitude inside your Debian chroot to do so.
Check info grub or man
lilo.conf for instructions on setting up the
bootloader. If you are keeping the system you used to install Debian, just
add an entry for the Debian install to your existing grub
menu.lst or lilo.conf. For
lilo.conf, you could also copy it to the new system and
edit it there. After you are done editing, call lilo
(remember it will use
lilo.conf relative to the system you call it from).
Installing and setting up grub is as easy as:
# aptitude install grub
# grub-install --recheck --no-floppy /dev/hda
# update-grub
The second command will install grub (in this case in
the MBR of hda). The last command will create a sane
and working /boot/grub/menu.lst.
Here is a basic /etc/lilo.conf as an example:
boot=/dev/hda6
root=/dev/hda6
install=menu
delay=20
lba32
image=/vmlinuz
label=Debian
Depending on which bootloader you selected, you can now make some
additional changes in /etc/kernel-img.conf.
For the grub bootloader, you should
set the do_bootloader option to no
.
And to automatically update your /boot/grub/menu.lst
on installation or removal of Debian kernels, add the following lines:
postinst_hook = update-grub
postrm_hook = update-grub
For the lilo bootloader, the value of
do_bootloader needs to remain yes
.
Check man yaboot.conf for instructions on
setting up the bootloader. If you are keeping the system you used to
install Debian, just add an entry for the Debian install to your
existing yaboot.conf. You could also copy it to
the new system and
edit it there. After you are done editing, call ybin (remember it will
use yaboot.conf relative to the system you call it from).
Here is a basic /etc/yaboot.conf as an example:
boot=/dev/hda2
device=hd:
partition=6
root=/dev/hda6
magicboot=/usr/lib/yaboot/ofboot
timeout=50
image=/vmlinux
label=Debian
On some machines, you may need to use ide0:
instead of hd:.
Finishing touches
As mentioned earlier, the installed system will be very basic. If you
would like to make the system a bit more mature, there is an easy method
to install all packages with standard
priority:
# tasksel install standard
Of course, you can also just use aptitude to install
packages individually.
After the installation there will be a lot of downloaded packages in
/var/cache/apt/archives/. You can free up some
diskspace by running:
# aptitude clean