By now you have probably heard of the new architectural innovation being brought to Failover Clustering in Windows Server 2008 R2 (download) known as Cluster Shared Volumes, or CSV. CSV functions as a distributed-access file system optimized for Hyper-V. A comparison would be to a clustered file system, however, unlike other clustered file systems, CSV does not use any proprietary technology – it uses standard NTFS, so there is nothing special you need to purchase or support – it just works! If your storage is suitable as a standard clustered disk, it can be used as a Cluster Shared Volume. In the past, only one node could host a virtual machine (VM) and access the VHD on the shared storage, so if another node needed to host the VM or access the disk, it would need to failover and it would affect every resource on that shared disk. With CSV in R2, any node can host the VM and any node can access the VHD on shared storage, so VM and disk ownership can move freely across cluster nodes without impacting any other resources on that shared disk.