----- "Bhaskar Jayaraman" <Bhaskar.Jayaraman(a)lsi.com&gt; wrote: As I've tried to stress in my previous responses, the Red Hat crash.ko module is most likely *not* necessary in your case -- but more on that below... With respect to the ramifications of applying xen-3.3.0 source code (which includes Xensource's 2.6.18-based kernel, right?) on top of the CentOS 5.2 source three, then it's to be expected that Xensource vmlinux kernel doesn't include the /dev/crash driver -- that's a Red Hat only concept. Sorry, I'm not going to be able to help you w/respect to upstream Xensource kernel building. Never done it, and I don't suppose I ever will... However, there are several upstream xen junkies on this list, and they may be able to help you out with generating a debug-full vmlinux. BTW, did you do the preliminary "make mrproper" like it requests? Anyway, getting back to the /dev/crash driver issue... Especially given that you are running on an x86_64, the course of least resistance is to utilize the built-in /dev/mem driver and forget about trying to shoe-horn the Red Hat /dev/crash driver into place. If /dev/mem doesn't work by default because the Xensource 2.6.18 vmlinux kernel has put restrictions on its use (like Red Hat does), then just remove those restrictions and rebuild. Dave