Ok, in my last post, I talked about what a runlevel is and what it does to your box. However, I never really mentioned why you should care, or how to to manage a specific runlevel. I plan on discussing those items here. First, is why you should care about runlevels. I’ve seen the argument that runlevels add nothing to your box, and managing services is trivial, so runlevels just add an extra layer of complexity. I disagree. For me, runlevels add a layer of dependability. The whole idea of runlevels is to maintain a level of predictability with your box. I should be able, at any given time during the day, predict what is running on my box. If not, then I’ve given up a level of security. By not knowing how my box is performing, or what it is executing, I’ve opened a door for potential vulnerability. However, if I can predict the state of my box, regardless of time of day, stress it’s under or number of users logged in, then I’ve maintained a level of security and dependability. As such, I’ve done my job well as a system administrator. Runlevels give me that predictability, as well as flexibility in the state I want my box operating under.