I'm going to be upgrading my Xen dom0 and it's domUs and want to make sure that I don't do this in the wrong order. Right now my domUs that are paravirtualized are using xen 3.1 and so is my dom0. I'm going to be upgrading to xen 4.0.2. Do I need to upgrade the dom0 first or the domU? Which way are things backwards compatible? I've done some searching this afternoon and haven't been able to find a definitive answer. You'd think it'd be right on the xen website stating which versions are compatible. Jon