CSV (Cluster Shared Volume) is fundamental of Microsoft Hyper-V. You must have it to leverage Live Migration and High Availability features. But it's very confuse when you want to reclaim CSV since CSV is using different name with physical disks. For example, CSV name usually is "Cluster Disk x" , path usually is "C:ClusterStorageVolumeX" . But real disk name is "Disk x" in Disk Manager . You have to very carefully when delete the disk.