If a VM becomes unavailable or fails in case of a disaster, you can fail over to a VM replica and quickly restore services in the production environment. When you perform failover, the VM replica takes over the role of the original VM. As a result, you have your VM up and running within a couple of minutes, and your users can access services and applications they need with minimal disruption.
Before you perform failover, check prerequisites. Then use the Hyper-V Failover wizard to fail over the VM replica.