Because I have some freezes because of vga passthrough lately, I tried to debug this but unfortunatly didn''t really found a working way: 1) Watching screen output for kernel messages That obviously didn''t work because i passed all my vgas to domUs and therefor didn''t see anything from dom0 / kernel. 2) Serial console In general a good idea, but i don''t have any serial connectors on my mainboard so this is not an option either. 3) Kdump I tried setting up kexec/kdump but a crashkernel part never showes up in /proc/iomem so kexec/kdump do not work. There is a line in xl dmesg saying: (XEN) Kdump: 128MB (131072kB) at 0x1000000 but despite that i don''t see any indication that crashkernel is working in any way.. I read somewhere that that kdump doesn''t work with newer pvops dom0 kernels at all, and i have read somewhere else that this is only an issue that the crashkernel space doesn''t show up in /proc/iomem but this the point kexec looks for.. So what I would like to know is a) if anyone got kdump working on a newer kernel with a newer xen and maybe what i am missing in my configuration b) if there is an other working way of debugging xen freezes or similar My system is a debian wheezy with a 3.7.4 vanilla kernel and latest xen-unstable.