Issue in the end was related to a high load VM causing some issues with resource management within virt. we've now load balanced this system out and it's performing as expected now.

The system is back online. We're digging into why this node went down.

System is being rebooted currently and will be offline for a couple moments.

We've observed a Virtfusion issue on this hypervisor. We're looking into it and will have this sorted asap.