Chapter 1. Boot Process, Init, and Shutdown

Chapter 1. Boot Process, Init, and Shutdown

1.1. The Boot Process
1.2. A Detailed Look at the Boot Process
1.2.1. The BIOS
1.2.2. The Boot Loader
1.2.3. The Kernel
1.2.4. The /sbin/init Program
1.3. Running Additional Programs at Boot Time
1.4. SysV Init Runlevels
1.4.1. Runlevels
1.4.2. Runlevel Utilities
1.5. Shutting Down

An important and powerful aspect of Red Hat Enterprise Linux is the open, user-configurable method it uses for starting the operating system. Users are free to configure many aspects of the boot process, including specifying the programs launched at boot-time. Similarly, system shutdown gracefully terminates processes in an organized and configurable way, although customization of this process is rarely required.

Understanding how the boot and shutdown processes work not only allows customization, but also makes it easier to troubleshoot problems related to starting or shutting down the system.