Re: Upgrading to a 2.6 Kernel on Debian testing

[steve]

Adrian Robertson wrote:
Jamie Dobbs wrote:
Hi
Can anyone point me to a simple howto on upgrading from Kernel 2.4.25 to
a 2.6 Kernel on Debian. I have attempted this in the past without any
success and would appreciate any help that I can find!
cheers
Jamie
 

The easy way is to use a Debian kernel image
'apt-cache search kernel image | grep 2.6' select the appropriate 
image then apt-get install it.
You will need to include a initrd statement in your bootloader.
In lilo it would look like this:
image=/vmlinuz
       initrd=/initrd.img
       label=Linux
       read-only

Adrian

I know that's what most of the installers do, but I recommend that you 
keep the boot stuff together in the /boot directory, and then address 
them directly in the lilo/grub.conf. The files should also identity the 
kernel you're using.

I've just noticed my mailserver's at 2.4.20, so here's a log of the update
1. vi /etc/lilo.conf...
Near the top...
Default=Linux
image=/vmlinux
  label=Linux
Now reads...
Default=Linux-2.4
image=/boot/vmlinux-2.4.20-bf2.4
  label=Linux-2.4
( I was going to copy /vmlinux to /boot/vmlinux..., but the file already 
existed. )

run lilo, and make sure there are no error messages.
Reboot, and make sure it boots up on this kernel
(if there was an initrd file, then I would have copied it to/checked for 
the existance of  /boot/initrd-2.4.25.img and modified that bit of 
lilo.conf as well. )

Then modify your lilo/grub.conf to that it boots these by default.
Reboot...! Make sure they work before you start.
Upgrade the kernel.
apt-get install kernel-image-2.6.7-1-686 kernel-headers-2.6.7-1 
module-init-tools ( I had to use the 386 kernel as it's a VIA chip on 
this server )

This added a few more modules to the list, then told me I had to 
download 17MB of stuff...

Some time later...
I got a message during the install, asking me whether I wanted to stop, 
as lilo.conf needs to be updated. Reply No ( not the default ) to this.
Then do I want to make a symbolic link to /initrd...  No way!
Install a boot block using the old lilo.conf... No
Throw away the current lilo.conf and install an new one? NO!

I now have files vmlinuz-2.6.7-1-i386 and initrd.img-2.6.7-1-i386 in /boot.
I'll now add a new block into /etc/lilo.conf, which is not the default 
boot block

The relevant bit of /etc/lilo.conf now reads...
default=Linux-2.4.20
                                                                                                                                                            

image=/boot/vmlinuz-2.4.20-bf2.4
       label=Linux-2.4.20
       read-only
                                                                                                                                                           

image=/boot/vmlinuz-2.6.7-1-386
       initrd=/boot/initrd.img-2.6.7-1-386
       label=Linux-2.6.7
       read-only
                                                                                                                                                            

run lilo
A * should come up against Linux-2.4.20 ( 25 in your case ), indicating 
it's the default, and no errors should occur. It should say it's added 
your Linux-2.6.7 definition.

Now's the acid test. Reboot time...!
As soon as the lilo prompt appears on the screen, press the shift key. 
Use the arrow keys to select the Linux-2.6.7 kernel from the list and 
hit return. If you're lucky, then the default kernel will work.

I'm glad to say, it did for me!
Grub will be slightly different, but the only fundamental difference is 
that there is no 'grub' command equivalent to 'lilo' to write the 
bootstrap changes to disk.

Hope this is of some use to you.
Cheers,
Steve