How do i change kernels?

matrim · 03-17-2007, 12:06 AM

I had to reinstall/upgrade so now i have the older kernel. up2date says i have the more current kernel installed also. How do I change it so the newer one loads?

sn68 · 03-17-2007, 12:08 AM

Edit: Misread the question

You will have to edit the grub.conf

cd into the boot directory and locate the kernel image, now open /etc/grub.conf
and copy paste the lines from title to initrd below and substitute the correct kernel version

sn68 · 03-17-2007, 12:21 AM

My grub.conf is as follows

Code:

# grub.conf generated by anaconda
#
# 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 (hd0,1)
#          kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
#          initrd /initrd-version.img
#boot=/dev/hda
default=0
timeout=5
splashimage=(hd0,1)/grub/modsplash.xpm.gz
#splashimage=(hd0,1)/grub/splash.xpm.gz
#hiddenmenu
title Fedora Core (2.6.19-1.2288.2.1.fc5)
        root (hd0,1)
        kernel /vmlinuz-2.6.19-1.2288.2.1.fc5 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
        initrd /initrd-2.6.19-1.2288.2.1.fc5.img
title Fedora Core (2.6.18-1.2257.fc5)
        root (hd0,1)
        kernel /vmlinuz-2.6.18-1.2257.fc5 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
        initrd /initrd-2.6.18-1.2257.fc5.img

when you cd into /boot and ls something like following will appear

Code:

[root@localhost boot]# ls
config-2.6.18-1.2257.fc5      initrd-2.6.19-1.2288.2.1.fc5.img  vmlinuz-2.6.18-1.2257.fc5
config-2.6.19-1.2288.2.1.fc5  lost+found                        vmlinuz-2.6.19-1.2288.2.1.fc5
grub                          System.map-2.6.18-1.2257.fc5
initrd-2.6.18-1.2257.fc5.img  System.map-2.6.19-1.2288.2.1.fc5

You can pickup the initrd & vmlinuz values of kernel not appearing in the grub menu and add them and reboot

matrim · 03-17-2007, 12:34 AM

Hi,
thanks for the help. There is no updated kernel img there(its the original 2.6.5). Did I lose it when I updated/reinstalled? And if so, why does up2date still show that it is installed?

sn68 · 03-17-2007, 12:46 AM

If its not there, then its better you do
yum -y install kernel

you can check installed kernels with
rpm -qa kernel

matrim · 03-17-2007, 01:23 AM

Sigh.
yum says most updated kernel installed, which is the 2.6.10. But its not. In the boot folder, I only have 2.5.8. Any other ideas? :/