As any system administrator (or hunchbacked henchman thereof) undoubtably knows, there are certain circumstances which, for whatever reason, aggrivate the god(s) of fate. In my brief time as an administrator's lacky, and bearer of the monitoring pager, I have learned a few of these circumstances. I provide them now for the sake of others.
Things that might cause a minor problem
Things that will cause a minor problem
Things that will cause a major problem