Posted by Hans-Henry Jakobsen
To upgrade a Debian Etch (stable) installation to testing Debian Lenny (unstable), you can do the following steps
sudo vi /etc/apt/sources.list
change all occurences of the word etch for lenny, or stable for testing
sudo apt-get update && apt-get dist-upgrade
That is all that is needed to upgrade Debian Etch to Debian Lenny which is expected to be released fall 2008. The process can be reversed if you would like to revert from Lenny to Etch, just change back your changes in sources.list
Tags: Debian, dist-upgrade, Etch, Lenny