Quoted: lsof is the Linux/Unix über-tool. I use it most for getting network connection related information from a system, but that's just the beginning for this amazing and little-known application. The tool is aptly called lsof because it "lists open files". And remember, in Unix just about everything (including a network socket) is a file.

Quoted: Explore the use of averages in performance analysis and capacity planning to understand how the load average can be reorganized to do better capacity planning.