This section explains how to install Debian GNU/Linux 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 GNU/Linux 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 GNU/Linux install. It's also a clever way for dealing with hardware that otherwise doesn't play friendly with various boot or installation media.
With your current *nix partitioning tools, repartition the hard drive as needed, creating at least one filesystem plus swap. You need at least 150MB of space available for a console only install, or at least 300MB if you plan to install X.
To create file systems on your 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.
The tool that the Debian installer uses, which is 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. Install wget and
ar if they aren't already on your current system,
then download and install debootstrap.
If you have an rpm-based system, you can use alien to convert the .deb into .rpm, or download an rpm-ized version at http://people.debian.org/~blade/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 binary files from it. You will need to have root privileges to install the binaries.
# ar -x debootstrap_0.X.X_arch.deb # cd / # zcat /full-path-to-work/work/data.tar.gz | tar xv
Note that running debootstrap may require you to have
a minimal version of glibc installed (currently
GLIBC_2.3). debootstrap itself is a shell script, but
it calls various utilities that require glibc.
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
http://www.debian.org/misc/README.mirrors.
If you have a sarge Debian GNU/Linux 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,
arm,
hppa,
i386,
ia64,
m68k,
mips,
mipsel,
powerpc,
s390, or
sparc.
# /usr/sbin/debootstrap --arch ARCH sarge \
/mnt/debinst http://http.us.debian.org/debian
Now you've got a real Debian system, though rather lean, on disk. Chroot into it:
# LANG= chroot /mnt/debinst /bin/bash
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 /mnt/floppy auto noauto,rw,sync,user,exec 0 0 /dev/cdrom /mnt/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
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
To configure your keyboard:
# dpkg-reconfigure console-data
Note that the keyboard cannot be set while in the chroot, but will be configured for the next reboot.
To configure networking, edit
/etc/network/interfaces,
/etc/resolv.conf, and
/etc/hostname.
# 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 /etc/resolv.conf:
search hqdom.local\000 nameserver 10.1.1.36 nameserver 192.168.9.100
Enter your system's host name (2 to 63 characters):
# echo DebianHostName > /etc/hostname
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.
Set your timezone, add a normal user, and choose your apt sources by running
# /usr/sbin/base-config new
To configure your locale settings to use a language other than English, install the locales support package and configure it:
# apt-get install locales # dpkg-reconfigure locales
NOTE: Apt must be configured before, ie. during the base-config phase. Before using locales with character sets other than ASCII or latin1, please consult the appropriate localization HOWTO.
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 kernel-image
Then install your choice using its package name.
# apt-get install kernel-image-2.X.X-arch-etc