With huge servers like IBM z there are many resources available so it was quite obvious to test the limits of libvirt. For example, one of the questions was how fast and how many minimal guests could be started in a short time period. How high is the system load for that? In times of CI and TDD this is especially interesting since thousands of guests are started and destroyed for regression tests.
This presentation will give an overview of bottlenecks in libvirt, what the reasons are and what problems came up during these tests.