The kernel RPM package configures the
boot loader to boot the newly installed kernel (except for IBM
eServer iSeries systems). 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 does not boot into Red
Hat Enterprise Linux properly. If this happens, boot the system
with the boot media created earlier and try configuring the boot
loader again.
All x86 systems use GRUB as the boot loader, which includes all
AMD64 systems.
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-hugemem package was installed, a section
exists 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=1
timeout=10
splashimage=(hd0,0)/grub/splash.xpm.gz
title Red Hat Enterprise Linux (2.6.9-5.EL)
root (hd0,0)
kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/
initrd /initrd-2.6.9-5.EL.img
title Red Hat Enterprise Linux (2.6.9-1.906_EL)
root (hd0,0)
kernel /vmlinuz-2.6.9-1.906_EL ro root=LABEL=/
initrd /initrd-2.6.9-1.906_EL.img
|
If a separate /boot/ partition was
created, the paths to the kernel and initrd image are relative to
/boot/.
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
first title section, set default to
0.
Begin testing the new kernel by rebooting the computer and
watching the messages to ensure that the hardware is detected
properly.
Itanium systems use ELILO as the boot loader, which uses
/boot/efi/EFI/redhat/elilo.conf as the
configuration file. Confirm that this file contains an image section with the same version as the
kernel package just installed:
prompt
timeout=50
default=old
image=vmlinuz-2.6.9-5.EL
label=linux
initrd=initrd-2.6.9-5.EL.img
read-only
append="root=LABEL=/"
image=vmlinuz-2.6.9-1.906_EL
label=old
initrd=initrd-2.6.9-1.906.img
read-only
append="root=LABEL=/"
|
Notice that the default is not set to the new kernel. To
configure ELILO to boot the new kernel, change the value of the
default variable to the value
of the label for the
image section that contains the
new kernel.
Begin testing the new kernel by rebooting the computer and
watching the messages to ensure that the hardware is detected
properly.
The IBM S/390 and IBM eServer zSeries systems use z/IPL as the
boot loader, which uses /etc/zipl.conf as
the configuration file. Confirm that the file contains a section
with the same version as the kernel package just installed:
[defaultboot]
default=old
target=/boot/
[linux]
image=/boot/vmlinuz-2.6.9-5.EL
ramdisk=/boot/initrd-2.6.9-5.EL.img
parameters="root=LABEL=/"
[old]
image=/boot/vmlinuz-2.6.9-1.906_EL
ramdisk=/boot/initrd-2.6.9-1.906_EL.img
parameters="root=LABEL=/"
|
Notice that the default is not set to the new kernel. To
configure z/IPL to boot the new kernel by default change the value
of the default variable to the
name of the section that contains the new kernel. The first line of
each section contains the name in brackets.
After modifying the configuration file, run the following
command as root to enable the changes:
Begin testing the new kernel by rebooting the computer and
watching the messages to ensure that the hardware is detected
properly.
The /boot/vmlinitrd-<kernel-version> file is installed
when you upgrade the kernel. However, you must use the dd command to configure the system to boot the new
kernel:
-
As root, issue the command cat
/proc/iSeries/mf/side to determine the default side (either A,
B, or C).
-
As root, issue the following command, where <kernel-version> is the version of the
new kernel and <side> is the
side from the previous command:
dd if=/boot/vmlinitrd-<kernel-version> of=/proc/iSeries/mf/<side>/vmlinux bs=8k
|
Begin testing the new kernel by rebooting the computer and
watching the messages to ensure that the hardware is detected
properly.
IBM eServer pSeries systems use YABOOT as the boot loader, which
uses /etc/aboot.conf as the configuration
file. Confirm that the file contains an image section with the same version as the
kernel package just installed:
boot=/dev/sda1
init-message=Welcome to Red Hat Enterprise Linux!
Hit <TAB> for boot options
partition=2
timeout=30
install=/usr/lib/yaboot/yaboot
delay=10
nonvram
image=/vmlinux--2.6.9-5.EL
label=old
read-only
initrd=/initrd--2.6.9-5.EL.img
append="root=LABEL=/"
image=/vmlinux-2.6.9-5.EL
label=linux
read-only
initrd=/initrd-2.6.9-5.EL.img
append="root=LABEL=/"
|
Notice that the default is not set to the new kernel. The kernel
in the first image is booted by default. To change the default
kernel to boot either move its image stanza so that it is the first
one listed or add the directive default and set it to the label of the image stanza that contains the
new kernel.
Begin testing the new kernel by rebooting the computer and
watching the messages to ensure that the hardware is detected
properly.
