Debian modifications needed before FreeLCS installation

Debian support was added in FreeLCS version 3.0. Later Debian releases are also supported by FreeLCS.

Canonical builds its Ubuntu releases using Debian software packages. Therefore both of these Linux distributions have much in common, but also have some differences. Some small config changes must be made to Debian before FreeLCS can be installed and run.

Remove cd / dvd installation media from sources.list

Debian adds the install cd / dvd as a available repository for software package installation. When you install new software then Debian first tries to find it on the installation cd / dvd. If the disk is not inserted, then installation stops with an error message. This prevents FreeLCS from installing the software packages it needs. The installation disk must be removed from the list of available installation sources. This list is a simple text file that can be manually edited.
Open the Terminal ( /Applications/Accessories/Terminal ) and get root provileges by giving the following command (will ask for root password):

su root

Open the installation source list to a text editor in the terminal with the following command:

nano -w /etc/apt/sources.list

Find lines that start with: deb cdrom and add a # character in front of each. This disables the line.
Example: the following line:

deb cdrom:[Debian GNU/Linux 13.0.0 _Trixie_ - Official amd64 NETINST with firmware 20250809-11:20]/ trixie contrib main non-free-firmware

becomes:

#deb cdrom:[Debian GNU/Linux 13.0.0 _Trixie_ - Official amd64 NETINST with firmware 20250809-11:20]/ trixie contrib main non-free-firmware

Save the modified file using the keyboard command: ctrl + o
Exit the nano - editor with keyboard command: ctrl + x

Install the sudo - program and add user to the sudo group

FreeLCS uses the sudo - program to get root permissions during installation. If sudo is not available then FreeLCS installation fails.

Debian installs sudo if you selected the 'Desktop' - installation during Debian install process. To ensure that sudo is installed, try to reinstall it:

Get root permissions with the following terminal command (asks for root password):

su - (Starting with Debian 10 you need to get root permissions by: su - or root-users path definitions may not be accessible and some commands might not be found)

Install the sudo package:

apt-get -y install sudo

The user account that you use to run the FreeLCS installer must have permission to run the sudo - program. This permission is given by adding the user to the group named 'sudo'. In the following example we assume that the name of this user account is 'john'. Change this name to your actual user account name.
Add the user account to the group 'sudo' with the following terminal command:

adduser john sudo

If you are logged in with the user account that you added to the group 'sudo', then you must now log out and back in for the changes to take effect.

If sudo installation gives you the error: "unable to locate package sudo", then some of the required package repositories are missing from the text file: /etc/apt/sources.list Below you can see an example of my working sources.list. You must run apt-get update after you make changes to the package repository settings so that the database for available packages gets updated.

Debian 13:

#deb cdrom:[Debian GNU/Linux 13.0.0 _Trixie_ - Official amd64 NETINST with firmware 20250809-11:20]/ trixie contrib main non-free-firmware

deb http://deb.debian.org/debian/ trixie main non-free-firmware
deb-src http://deb.debian.org/debian/ trixie main non-free-firmware

deb http://security.debian.org/debian-security trixie-security main non-free-firmware
deb-src http://security.debian.org/debian-security trixie-security main non-free-firmware

# trixie-updates, to get updates before a point release is made;
# see https://www.debian.org/doc/manuals/debian-reference/ch02.en.html#_updates_and_backports
deb http://deb.debian.org/debian/ trixie-updates main non-free-firmware
deb-src http://deb.debian.org/debian/ trixie-updates main non-free-firmware

# This system was installed using small removable media
# (e.g. netinst, live or single CD). The matching "deb cdrom"
# entries were disabled at the end of the installation process.
# For information about how to configure apt package sources,
# see the sources.list(5) manual.

If you did not install a graphical desktop during Debian install, then you need to do two more modifications described below. If you did install a graphical desktop then you can go ahead with the normal FreeLCS install procedure described in the user manual :)

Fixing Debian / Ubuntu locale

Debian and Ubuntu 16.04 and newer locale can be fixed by using the method described below.

If you installed a graphical desktop during Debian installation, then your locale should be configured correctly, if not then you should configure it before FreeLCS installation. Locale error messages during program package installation stops the FreeLCS installer.

Run the command:

su - (On debian)

sudo su (On Ubuntu)

dpkg-reconfigure locales

Select your locale from the list. Search for your language and the text "UTF-8". I have selected the Finnish language (fi_FI.UTF-8) in the picture below.

Next window asks you to decide which locale is the system default. In the picture below I chose the default to be english us.

Now you need to log out and back in for the locale changes to take effect.

If you installed Debian graphical desktop then continue with normal install instructions here. If you didn't install a graphical desktop then follow the headless installation instructions here.