Package selection

If the provider offers a “minimal” default installation of “Ubuntu 20.04 (Focal Fossa)”, this can be taken as base system. Further package deinstallation is more trouble than it’s worth. Independent from the provider also exists a minimalistic Ubuntu server distribution as base to install: Ubuntu Server 20.04 LTS

Integrate package repositories

(To deepen see also: Wiki)

It is recommended to use a mirror server in the area instead of the Canonical server, since mostly the connection is faster, and cost and bandwidth for the main server will be reduced. The example server chosen here is located in Germany (Aachen), making it suitable for central Europe.

Hint: Many Ubuntu installations use the command sudo to get administrator permissions. In this case in front of the commands mentioned here, the word sudo must be typed. In the next tutorial part „User + SSH“ we will configure a fully-fledged root account, and sudo will become obsolete.

Actual list of official mirror servers: https://launchpad.net/ubuntu/+archivemirrors

Enter repositories: /etc/apt/sources.list (Wiki: https://help.ubuntu.com/community/Repositories/CommandLine)
(Hint: Repositories which are needed only sometime or optional explanatory notes can be commented out with the # character at the beginning of a line.)

deb http://ftp.halifax.rwth-aachen.de/ubuntu focal main restricted universe multiverse
deb http://ftp.halifax.rwth-aachen.de/ubuntu focal-updates main restricted universe multiverse
deb http://ftp.halifax.rwth-aachen.de/ubuntu focal-security main restricted universe multiverse
deb http://ftp.halifax.rwth-aachen.de/ubuntu focal-backports main restricted universe multiverse

After changing the repositories, the new selection must be loaded again into the package manager:

apt-get update

Install Software Packages

Most likely in the new choosen repositories updates are available for some packages. These should be installed first of all:

apt-get upgrade

Install the following packages (and their dependencies) with:

apt-get install mariadb-server tmux

For OpenSim up to version 9.2 additionally install Mono:

apt-get install mono-complete

For OpenSim version 9.3, instead .NET 6.0 is required. This must be installed from a Microsoft repository, which must therefore be referenced beforehand:

wget https://packages.microsoft.com/config/ubuntu/20.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
dpkg -i packages-microsoft-prod.deb
rm packages-microsoft-prod.deb
apt-get update

apt-get install dotnet-runtime-6.0 libgdiplus

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Continued: Manage user accounts and hardening SSH