Linux /etc/inittab file

One of the files that the average Unix sysadmin rarely looks at, almost never changes and yet depends on every time he or she reboots a system is the /etc/inittab file. This modest little file controls what happens whenever a system is rebooted or forced to change run levels. Let's take a look at the configuration lines that tell your system what it's supposed to do when you hit that power button.

NOTE: The /etc/inittab files on Solaris and other Unix systems that share this way of booting follow the same general rules and most of what is described below applies equally well to those Unix variants.