Hi Jens,

Thanks, indeed this diagram is't about CPU utilization. All other diagrams aren't showing any peaks, CPU usage is even scarely low (1% user, 1% nice, 1% system over the whole day, which would make me think the graphing is broken). Both systems are identical and have an Adaptec 5805 controller, maybe that has something to do with it.. Not sure, I'll keep an eye on it, thanks for the suggestions.