Windows Server 2012 Hyper-V Role introduces a new capability, Hyper-V Replica, as a built-in replication mechanism at a virtual machine (VM) level. Hyper-V Replica can asynchronously replicate a selected VM running at a primary site to a designated replica site across LAN/WAN. Here both a primary site and a replica site are Windows Server 2012 Hyper-V hosts where a primary site runs production or the so-called primary VMs, while a replica site is standing by with replicated VMs off and to be brought online, should the primary site experiences a planned or unplanned VM outage. Hyper-V Replica requires neither shared storage, nor a specific storage hardware. Once an initial copy is replicated to a replica site and replication is ongoing, Hyper-V Replica will replicate only the changes of a configured primary VM, i.e. the deltas, asynchronously. The following schematic presents this concept.

Once all the requirements are put in place, first configure a target replica server, followed by configure an intended VM at a primary site for replication. A sample process to establish Hyper-V Replica is available at http://aka.ms/replica.