This image is used as reference. In the build and test automation one has to get the clean image, start it, install the more "dynamic" modules, i.e. the system under development and test, and execute the (integration) tests in the virtualisation, then collect the test results and shutdown the virtual system again. That procedure allows deterministic test-scenarios on different machines, also (or particularly) on a continuous integration server.
In an initial research I did not find much tools in that area, any ideas?