DTrace

I so much regret that the course I'm running today is not on Solaris 10 (but Solaris 9).
We are running on what appears to be a totally idle system, dedicated to training, with no heavy applications even installed, let alone running.
There is 9 of us, doing things that any ordinary script writer would do (you guessed it - it's a shell scripting course). That does not include putting the system under any big strain.
Yet for some 10-15 minutes this morning the system was running visibly slower. The server is in London, we are not. We don't have access to root either. So we have all of the standard tools: ps, prstat, uptime, and few more, but none of them managed to pinpoint what was going wrong. And then it sorted itself out.
We could only assume there was some background task running, doing some system maintenance stuff (at 11AM though ?), generating LOADS of very short-lived tasks that ordinary diagnostic tools couldn't register. I wished I had DTrace available!
Mind you - I have learned a bit more about prstat today...