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.
