It’s Dangerous to Go Alone - Exploring /proc with Friends

Ever wondered how your everyday system tools know how much CPU or Memory a process is using? Do you need to know which processes are using swap space? Recover an open file that may have been deleted? What about just a general better understanding of what’s going on with your system? Let’s talk about the Linux wonderfulness that is /proc. We will go over the directory layout, important files as well as kernel tuneables. The importance of /proc will be reinforced by using strace to show how common commands can pull information form /proc to learn about the runtime of the system. On screen strace will be used to dissect programs such as w and ps and see what files they call from proc to gather their information. The files that are identified will be elaborated on. After seeing how common programs use /proc we will go over how a system admin can use proc to find out which process is using the most swap space or recover a deleted file still being helped open.