FYI all we're working on xen1's issues. They seem to be iscsi related but its still not quite clear. Basically the last thing we see in the logs is an issue with iscsi, then the box reboots. We're seeing similar log issues around the same time on our other boxes... but they don't reboot. See: https://fedorahosted.org/fedora-infrastructure/ticket/334 -Mike