Q: Now that Windows Server 2012 Hyper-V supports SMB 3.0 file shares, can I use DFS-R to replicate virtual machines?
A: Distributed File System Replication (DFS-R) is part of the overall DFS technology (the other being the DFS namespace capability) that allows the replication of files using remote differential compression, which means only changes to files are replicated.
DFS-R, however, can't be used with Windows Server 2012 Hyper-V virtual machines (VMs) because DFS-R works only with closed files. The files associated with a VM are kept open and therefore wouldn't be replicated until stopped. For replication of VMs between locations, look at Hyper-V Replica. You might also be interested in reading "Q: How do I set up Hyper-V Replica?" and "Q: Is there a hard limit on the number of Hyper-V Replica servers that can be enabled from a specific Hyper-V server?"
See more FAQs at John Savill's page.