Whenever you hear about Linux, you’ll also hear about LILO. LILO is the boot loader Linux uses to load the operating system kernel. Whenever you change or move the Linux kernel, you must invoke LILO to rebuild a map of the kernel locations. LILO is versatile—it can boot Linux kernels from any type of filesystem, including floppy disk, as well as from other operating systems. This chapter looks at LILO, the way hard disks are laid out with Linux, the boot process, the most common boot processes, and LILO’s interactions with each. This information should help you install and use LILO effectively.

Several versions of LILO are available. Most current versions support one of two different directory structures. The more traditional (and older) structure resides in the /etc/lilo directory. The newer structure has files scattered in several directories, including /etc, /sbin, and /boot. Because the older /etc/lilo structure is the most common, it is used for examples in this chapter. If you are using the new structure (check for the existence of /etc/lilo), substitute the new pathnames as necessary.