When an instance (virtual machine) fails in a Vantage delivered as-a-service system, we replace the failed node with the “Hot Standby Node” that is usually already present. We also detach the disks and NICs from the failed node, attach it to the new node and bring the cluster up. This process typically results in ~10 mins of downtime. Once the system is up, we spin up another Hot Standby Node in the background.