Chapter 2. The GRUB Boot Loader

When a computer with Red Hat Enterprise Linux is turned on, the operating system is loaded into memory by a special program called a boot loader. A boot loader usually exists on the system's primary hard drive (or other media device) and has the sole responsibility of loading the Linux kernel with its required files or (in some cases) other operating systems into memory.

2.1. Boot Loaders and System Architecture

Each architecture capable of running Red Hat Enterprise Linux uses a different boot loader. The following table lists the boot loaders available for each architecture:

Architecture Boot Loaders
IBM® eServeriSeries OS/400®
IBM® eServerpSeries YABOOT
IBM® S/390® z/IPL
IBM® eServerzSeries® z/IPL
Intel® Itanium ELILO
x86 GRUB

Table 2-1. Boot Loaders by Architecture

This chapter discusses commands and configuration options for the GRUB boot loader included with Red Hat Enterprise Linux for the x86 architecture.