Anyway, anyone using “lenny” or “testing” and wanting to update xen; here are a few tips to make the transition a breeze:

• The debian wiki is full of useful information regarding xen
• backports.org has a current xen kernel (linux-image-2.6.32-bpo.4-xen-amd64) that works fine with xen 3.4, just follow the instructions on backports.org on how to add it to apt.
• I had to deactivate the “vfb” (VNC console) setting in the domU config files to get my guests to boot, browsing the Internet I saw people having the same problem with the “dhcp” setting.
• If you are planning on updating the guests kernels too (advised), remember to change the “kernel” and “ramdisk” settings in the domU config files accordingly

With these few points in mind, the update is a breeze.

While it is nice that I found the problem, it was a pain narrowing down the culprit. The last few days I had noticed that my server was dead in the water every morning and had at first suspected vmware, since I had installed that a few days ago on the server (and had to make a new kernel to get it running). Well, everything is fine now. Next time I have to update my kernel, I’ll remember to do a test run of /etc/cron.daily