Most recent versions of Linux, including the one supplied on this book’s CD-ROM, let you manage LILO through a menu-driven routine usually started through setup. Typically, when you have made any changes to the installation (such as adding new software), the last component of the setup program asks you whether you want to work with LILO. Figure 4.3 shows this screen.

Figure 4.3.
Whenever you make changes to Linux through the setup utility, it asks whether you want to use LILO.

From the menu-driven system shown in Figure 4.3, select the Begin option. Usually, the first thing the program asks for is any boot-time instructions that need to be specified when Linux starts, as shown in Figure 4.4. Normally, there are no boot-time instructions, but if you had to enter any parameters to start the Linux installation process, specify the same options here.

Figure 4.4.
The LILO installation process starts by asking whether you need any special boot-time instructions.

The next prompt, shown in Figure 4.5, asks where you want your LILO instructions written. The primary options were discussed earlier in the chapter. This version of LILO lets you select the Master Boot Record (MBR), the master sector of the primary Linux partition (called a superblock on this screen), or a floppy disk. The method you select depends on how you want Linux to start and whether it coexists with another operating system. For a minimal impact on your system, select the floppy disk boot option. This option requires you to place the boot floppy disk in the floppy disk drive when starting the machine, but then it boots cleanly into Linux. If the boot floppy disk is left out of the floppy disk drive, any other active partition (such as DOS or OS/2) is booted. Because the LILO instructions are only written to floppy disk with this approach, existing MBRs or partition boot sectors don’t change at all. This approach makes it very easy to remove Linux and prevent problems with other operating systems that exist on your drives.

Figure 4.5.
You are asked where you want to install LILO.

If you are installing only Linux, or plan to have very rare use of existing DOS or OS/2 partitions, use the Master Boot Record of partition boot sector. The only drawback to this approach is that, you must low-level format your hard drive if you want to remove Linux in the future. The Linux MBR is not compatible with DOS’.

A compromise is to use the partition boot sector (superblock). This approach lets you boot straight into Linux when the partition is active or use fdisk to activate any other partition. Although this option has more impact than the floppy disk boot option, yo can easily remove it by reformatting the partition and installing a new operating system.

If you are installing Linux to experiment with it and you are not sure whether you will leave it on your hard drive, use the boot floppy disk. This option provides the most hassle-free approach for backing out of Linux in the future. You can always rerun LILO and write the boot instructions to the MBR or superblock later.

The LILO system asks you whether you want a delay before Linux starts to boot, as shown in Figure 4.6. You can decide to not pause, to wait either 5 or 30 seconds, or to wait until LILO is told explicitly to boot. This last option is useful if you have two operating systems on your hard drive because it saves you from fooling around with fdisk to alter the active partition. A good compromise is either 5 or 30 seconds.

Figure 4.6.
You can set a delay before booting into Linux with one of the options shown in this menu.

After you set the delay, LILO returns you to the main LILO menu (shown in Figure 4.3). The next step is to identify the partitions that LILO will know about. The menu lists three operating systems: DOS, OS/2, and Linux. If you have either DOS or OS/2, you can give the partition information to LILO to allow it to boot this operating system instead of Linux (assuming you have a delay in the boot process). Begin with the Linux operating system, though. Select Linux on the menu (the menu choices are in order of most common use from top to bottom, generally) to display the Linux partition information screen shown in Figure 4.7.

Figure 4.7.
Use this screen to identify the boot Linux partition. In this example, only a single Linux data partition exists.

The example shown in Figure 4.7 shows a single Linux data partition on the hard drive, called /dev/sda3. The Linux swap partitions never show up on these lists (unless they were misidentified when they were installed). Enter the name of the Linux partition that is to be used for the boot partition (in the example, /dev/sda3 would be typed in the entry field). The next screen, shown in Figure 4.8, asks for a name for this partition. This name is used to identify the partition at boot time. For Linux partitions, just enter the word Linux to provide an unambiguous name for the partition.

Figure 4.8.
You need to assign a name to the Linux partition.

After entering the partition name, you are back to the main LILO menu. Now, add any other operating systems, such as DOS or OS/2. To install a DOS partition, for example, select DOS from the menu. A screen very similar to the one for selecting the Linux partition appears, as shown in Figure 4.9. Enter the name of the DOS partition (in this case, /dev/sda1).

Figure 4.9.
When you add another operating system to LILO, the partitions that apply are displayed. You can add this partition to the LILO boot table.

After the partition has been identified, name the partition as shown in Figure 4.10. Again, a simple name is best, so enter DOS or OS/2 as applicable. Don’t bother with fancy names; they are more trouble than they are worth!

Figure 4.10.
As with the Linux partition, you need to assign a name to the other partitions LILO will know about.

After you name all the partitions, you are brought back yet again to the LILO menu. The next step is to install the LILO information. Select the Install option from the menu. The system writes all the partition details you’ve supplied, and then you can exit LILO. The other options on the LILO menu allow you to modify an existing LILO table. In most cases, it’s easier to just start again. You can use this automated LILO installation any time you want. Take care that you enter the proper information, though, as an error can make it impossible to access a partition. Keep an emergency boot disk handy!