Linux Loader LILO

This chapter will help you if you chose not to install LILO when you first installed Red Hat Linux or if you need help in properly starting Linux with certain kernel options. You’ve probably already decided how you want to start Linux on your computer, but you should know that there are other ways to fire up your system. Instead of using LILO, you can start Linux from DOS with LOADLIN.EXE, which is included on your CD-ROM under the Dosutils directory. I’ll discuss LOADLIN.EXE later in this chapter in the section “Using LOADLIN.EXE to Boot Linux.”

You can also use your computer as a diskless workstation by booting Linux over a network. A discussion on this subject is beyond the scope of this chapter, but you’ll find the details on how to do this in Robert Nemkin’s Diskless-HOWTO, under the /usr/doc/HOWTO/mini directory after you install Linux.

Yet another approach is to use a commercial boot loader, such as V Communications, Inc.’s System Commander, which can come in handy if you need to run other operating systems such as OS/2, Solaris, or Windows NT on your computer. LILO has capabilities similar to commercial solutions, but it’s free. For now, I’ll assume that you’re going to use LILO to boot in one of three traditional ways. You can use LILO to start Linux

s From the Master Boot Record (MBR) of your hard drive

s From the superblock of your root Linux partition on your hard drive

s From a floppy disk

In the following section, I’ll show you a list of LILO’s configuration parameters and its command-line arguments, and I’ll point out some special features.

Installing and Configuring LILO Although LILO is easy to install by using the lilo command (located under the /sbin directory), you should first take the time to read its documentation, which you’ll find under /usr/doc. Along with the documentation, you’ll also find a shell script called QuickInst, which can be used to replace an existing LILO installation or for a first-time install. LILO’s documentation contains details of its features and provides important tips and workarounds for special

problems, such as installing boot loaders on very large capacity hard drives or booting from other operating systems.

WARNING

Before trying anything with LILO, you should have an emergency boot disk. Having a system that won’t boot is not much fun, and if you don’t have a boot disk, you might think that there is no possible way to get back in and change things. Spending a few minutes to make yourself a boot disk can save you a big headache down the road. Whatever happens, don’t panic! If you need to rescue your system, see Chapter 4, “System Startup and Shutdown,” for details.

If you don’t install LILO during your Red Hat install or decide not to use the QuickInst script, there are two basic steps to install LILO:

1. Configure /etc/lilo.conf.

2. Run /sbin/lilo to install LILO and make it active.

This discussion describes modifying an existing lilo.conf file. Before making any changes, do yourself a favor and create a backup of the file either in the same directory or on a separate disk. Several files are important to LILO and are created during an initial install:

3

s map installer; see man lilo for more information

/sbin/lilo—A

s /boot/boot.b—A boot loader

LILO

s /boot/map—A boot map, which contains the location of the kernel

s /etc/lilo.conf—LILO’s configuration file