Just a few notes on how to move your sonar installation to another machine without loosing any of your config and/or history. Some of that include the normal installation steps too. This list is specific to debian.

Add the sonar debian repo to your machine (/etc/apt/sources.list.d/sonar)

deb http://downloads.sourceforge.net/project/sonar-pkg/deb binary/

Update and install sonar (sonar pkg is not signed):

aptitude update && aptitude install sonar

Install postgresql and set up an account for your sonar: