kernel

 

kernel


 

Verifying 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 is configured incorrectly, the system will not boot into Red Hat Linux properly. If this happens, boot the system with the boot diskette created earlier and try configuring the boot loader again.

 

GRUB

If GRUB is used as the boot loader, confirm that the file /boot/grub/grub.conf contains a title section with the same version as the kernel package just installed (if the kernel-smp or kernel-bigmem package was installed as well, a section will exist for it as well):

 # Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/hda2
#          initrd /initrd-version.img
#boot=/dev/hda
default=3
timeout=10
splashimage=(hd0,0)/grub/splash.xpm.gz
title Red Hat Linux (2.4.20-2.47.1)
        root (hd0,0)
        kernel /vmlinuz-2.4.20-2.47.1 ro root=LABEL=/
        initrd /initrd-2.4.20-2.47.1.img
title Red Hat Linux (2.4.20-2.30)
        root (hd0,0)
        kernel /vmlinuz-2.4.20-2.30 ro root=LABEL=/
        initrd /initrd-2.4.20-2.30.img

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

Notice that the default is not set to the new kernel. 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 default to 1.

Begin testing the new kernel by rebooting the computer and watching the messages to ensure that the hardware is detected properly.

 

LILO

If LILO is used as the boot loader, confirm that the file /etc/lilo.conf contains an image section with the same version as the kernel package just installed (if the kernel-smp or kernel-bigmem package was installed, a section will exist for it as well):

 prompt
timeout=50
default=2.4.20-2.30
boot=/dev/hda
map=/boot/map
install=/boot/boot.b
message=/boot/message
linear

image=/boot/vmlinuz-2.4.20-2.47.1
        label=2.4.20-2.47.1
        initrd=/boot/initrd-2.4.20-2.47.1.img
        read-only
        append="root=LABEL=/" 
image=/boot/vmlinuz-2.4.20-2.30
        label=2.4.20-2.30
        initrd=/boot/initrd-2.4.20-2.30.img
        read-only
        append="root=LABEL=/"

Notice that the default is not set to the new kernel. 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. Run the /sbin/lilo command as root to enable the changes. After running it, the output will be similar to the following:

 Added 2.4.20-2.47.1 *
Added linux

The * after 2.4.20-2.47.1 means the kernel in that section is the default kernel that LILO will boot.

Begin testing the new kernel by rebooting the computer and watching the messages to ensure the hardware is detected properly.

 

Downloading the Upgraded Kernel

There are several ways to determine if there is an updated kernel available for the system.