How do you downgrade Linux Kernels

[Acoshi]

How do you downgrade from the Feodra Core 3 Kernel Module 2.6.11-1.27 to 2.6.11-1.20?

 

[Nothinman]

Install the older kernel and reboot into it, you can have as many kernels installed as you want.

 

[Hyperblaze]

Long version: download a less recent kernel from kernel.org or something
unarchive the kernel tar.gz file to /usr/src/

cd into kernel directory
type make menuconfig
select all the options you want.
after saving changes type
make && make modules_install
cp arch/i386/boot/bzImage /boot/whatever_file_you_want_to_call_it

if you are using grub make sure to add an entry to /boot/grub/grub.conf which links to the older kernel

if you are using lilo add an entry to /etc/lilo.conf (don't forget to run "lilo" at the end to refresh boot loader)

 

[Nothinman]

Or skip all of that and just install the FC RPM for the kernel you want.

 

[Hyperblaze]

Originally posted by: Nothinman
Or skip all of that and just install the FC RPM for the kernel you want.

i never did like a simple solution 😉

 

[Acoshi]

How would you edit your grub.conf to boot to the older kernel?

 

[Nothinman]

Look at the existing entry, make a copy of it and change the versions to match the one you want. I know Debian includes a tool to do this for you (update-grub) but I don't know if FC has something similar.

 

[TGS]

The kernel update RPM is by far the easiest solution. I mean seriously easy. You may just have to download the sources, if you don't already have the 2.6.11-1.20.


After you do a manual compile. For grub...


Check /boot/grub/grub.conf

There should be a line under whatever your first boot option like this:

title Red Hat Linux (2.6.11-1.27)
root (hd0,0)
kernel /vmlinuz-2.6.11-1.27 ro root=/dev/hda3
initrd /initrd-2.6.11-1.27.img

add the lines


title Red Hat Linux (2.6.11-1.20)
root (hd0,0)
kernel /vmlinuz-2.6.11-1.20 ro root=/dev/hda3
initrd /initrd-2.6.11-1.20.img

*disclaimer* just copy and paste the kernel and initrd lines version into second grub entry. As your kernel may not be on /dev/hda3 as in the example.

This will allow you to continue to boot by default into the original kernel, and boot into the older one when you pick it in the graphic menu. This is IMO highly recommended after doing kernel changes. *Highly*

 

[Hyperblaze]

Originally posted by: Acoshi
How would you edit your grub.conf to boot to the older kernel?

vi (or your editor of choice) grub.conf

and there should be an existing entry for your current kernel.

copy/paste or just type another entry with the older kernel.

 

[Acoshi]

Thanks for the quick responses guys!

I was able to rollback my kernel module using the advice given.

 

[Basie]

I Usually don't have much luck compiling Kernels. I remember only having success once and then after
many more attempts I gave up. So now I do it the easy way by following the advice given here. I couldnt figure out why they didnt work thinking that I followed all the necessary steps so I just got
discouraged. The Kernel Update RPM for me works fine.