Configuring the Boot Loader

The kernel RPM package configures the GRUB or LILO boot loader to boot the newly installed kernel if either boot loader is installed. However, it does not configure the boot loader to boot the new kernel by default. It is always a good idea to confirm that the boot loader has been configured correctly. This is a crucial step. If the boot loader has been configured incorrectly, you will not be able to boot your system. If this happens, boot your system with the boot diskette you created earlier and try configuring the boot loader again.

GRUB

If you selected GRUB as your boot loader, confirm that the file /boot/grub/grub.conf contains a title section with the same version as the kernel package you just installed (if you installed the kernel-smp and/or kernel-bigmem packages, you will have a title section for that package has well):

# NOTICE:   You have a /boot partition.      This means that #           all kernel paths are relative to /boot/ default=0 timeout=30 splashimage=(hd0,0)/grub/splash.xpm.gz title Red Hat Linux (2.4.18-7.95)           root (hd0,0)           kernel /vmlinuz-2.4.18-7.95 ro root=/dev/hda3           initrd /initrd-2.4.18-7.95.img

If you created a separate /boot partition, the paths to the kernel and initrd image are relative to the /boot partition.

To configure GRUB to boot the new kernel by default, change the value of the default variable to the title section number for the title section that contains the new kernel. The count starts with 0. For example, if the new kernel is the second title section, set the default to 1. You can begin testing your new kernel by rebooting your computer and watching the messages to ensure that your hardware has been detected properly.

LILO

If you selected LILO as your boot loader, confirm that the file /etc/lilo.conf contains an image section with the same version as the kernel package you just installed:

boot=/dev/had map=/boot/map install=/boot/boot.b prompt timeout=50 message=/boot/message linear default=linux image=/boot/vmlinuz-2.4.18-7.95  label=linux           initrd=initrd-2.4.18-7.95.img  read-only  root=/dev/hda5

The kernel RPM package activates the changes by running the command /sbin/lilo. To configure LILO to boot the new kernel by default, set the default variable to the value of label in the image section for the new kernel. You must run the /sbin/lilo command as root in order to enable the changes. After running it, you will see output similar to the following:

Added linux *

The * after linux means that the section labeled linux is the default kernel that LILO will boot. You can begin testing your new kernel by rebooting your computer and watching the messages to ensure your hardware has been detected properly.