I had blogged about my previous upgrade from Ubuntu 8.10 Intrepid to Ubuntu 9.04 Jaunty. Well, I'm pleased to say that I have had similar results with my upgrade from Ubuntu 9.04 Jaunty to Ubuntu 9.10 Karmic.
100% of my server services all functioned correctly after the upgrade. DNS/DHCP, HTTP, MySQL, Samba and (thankfully) Firewall all upgraded and worked "out of the box" The entire upgrade process took less than an hour too, which was very impressive. I was quickly able to drop in a couple of the needed 3rd party PPAs that I like to use, and after that all my applications and services are up and running as expected.
One thing that I did notice, was the old MadWiFi card didn't have the "ath_pci" module anymore. A quick Google search turned up this post, and I was able to get my drivers in place and my firewall/hostapd restarted so that my wifi was back up and running. I've been checking over things all day today, and so far I've failed to find anything that isn't working correctly.
Again, outstanding job Ubuntu Server Team :exmark: