A little back ground: I like Xen - works (almost) great on my hardware. However there is a few bugs that still exist in the Ubuntu kernels, that newer kernels don't have. I've been told (via IRC) that SUSE (Open in my case) has some of the best support for Xen in it's kernels. So I'm documenting my Jurny in updating my Ubuntu Xen machine's Kernel to a newer OpenSuse Kernel:
First off, You need to download the new RPM from the website. The following link will give you a list of Xen Kernels for the [Almost] latest version of OpenSuse: http://software.opensuse.org/search?baseproject=openSUSE%3A11.0&p=1&q=Kernel-xen Look for the one with the highest number - At this time it is: kernel-xen-2.6.25.20-13.1.i586.rpm
Download and extract the RPM into a temp directory: (Need to figure this one out - I use Midnight Commander, and I was able to enter the RPM, then enter the CPIO file, extracting tha data from there)
Once you have the extracted Directories (/boot, /etc, /lib, /usr) copy them to the root drive. There shouldn't be any duplicate files.
Ubuntu provides two scrtipts you need to run next;
Create a initrd.img file for the kernel by running: update-initramfs -k [kernel name] -c
Look for the installed System.map file to find the name, in this case it is 2.6.25.20-13-xen
Update your grub by running: update-grub
[At this point, I did things in the wrong order so I Crashed, I'll update this after I test again.]
Update 1: - I just rebooted the server after re-running the update-grub command. This time, I got a full boot, but Xend didn't seem work. I'll need to work on this issue next.