Configuring The Boot Loader - Red Hat LINUX 7.2 - OFFICIAL LINUX CUSTOMIZATION GUIDE Manual

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If you plan to upgrade the kernel-headers, kernel-source, and kernel-docs packages,
you probably do not need to keep the older versions. Use the following commands to upgrade these
packages (the versions might vary):
rpm -Uvh kernel-header-2.4.7-3.i386.rpm
rpm -Uvh kernel-source-2.4.7-3.i386.rpm
rpm -Uvh kernel-docs-2.4.7-3.i386.rpm
If you are using PCMCIA (for example, a laptop), you also need to install the kernel-pcmcia-cs
and keep the old version. If you use the -i switch, it will probably return a conflict because the older
kernel needs this package to boot with PCMCIA support. To work around this, use the --force
switch as follows (the version might vary):
rpm -ivh --force kernel-pcmcia-cs-3.1.24-2.i386.rpm
If you are using a SCSI controller, you need an initial RAM disk. The purpose of the initial RAM
disk is to allow a modular kernel to have access to modules that it might need to boot from before the
kernel has access to the device where the modules normally reside.
The initial RAM disk is created by using the mkinitrd command. However, the Red Hat RPM
package performs this step for you. To verify that it was created, use the command ls -l /boot.
You should see the file initrd-2.4.7-3.img (the version should match the version of the kernel
you just installed).
Now that you have installed the new kernel, you need to configure the boot loader to boot the new
kernel. Refer to Section 23.5, Configuring the Boot Loader for details.

23.5 Configuring the Boot Loader

Now that you have the new kernel installed, you must configure the boot loader to boot the new kernel.
This is a crucial step. If you do not perform this step or if you perform it 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.
In order to provide a redundant boot source to protect from a possible error in a new kernel, you should
keep the original kernel available. During the installation of Red Hat Linux 7.2, you had the option to
choose either LILO or GRUB as your boot loader. Refer to the appropriate section that follows.
23.5.1 GRUB
If you selected GRUB as your boot loader, you need to modify the file /boot/grub/grub.conf.
The default GRUB configuration file looks similar to the following:
# NOTICE:
#
default=0
You have a /boot partition.
all kernel paths are relative to /boot/
Chapter 23:Ugrading the Kernel
This means that