3.1.1.4.2.1 Volume Object Enumeration
QueryVolumesSupportedForSnapshots returns an instance of the IVssEnumMgmtObject interface. This interface is used to enumerate through a list of VSS_MGMT_OBJECT_PROP structures, which in turn, contain a VSS_MGMT_OBJECT_UNION structure, each of which contains a VSS_VOLUME_PROP.