I have a KVM/Qemu host running 4 Windows Server 2012 guests and after upgrading the host from Ubuntu 12.04 to 14.04 I get blue screens with a bug check string of "driver_irql_not_less_or_equal" that is caused by driver "viostore.sys". I don't want to stay on 12.04 for ever. What can I do?
viostore.sys is the virtio driver for storage (hard disks). Canonical provides a 3 years old version of virtio drivers compared to Redhat/centos. I've installed CentOS 7 on another host migrated the guests there and upgraded the virtio drivers to the latest stable version (0.1.96 at the time of writting). Problem solved :-) I'm not sure if I could use RedHat's virtio drivers in Ubuntu. I guess I could but to stay on the safe side and to try CentOS I also switched the OS.