The VSS_DIFF_VOLUME_PROP structure defines the properties of a shadow copy storage volume.

 typedef struct _VSS_DIFF_VOLUME_PROP {
   VSS_PWSZ m_pwszVolumeName;
   VSS_PWSZ m_pwszVolumeDisplayName;
   LONGLONG m_llVolumeFreeSpace;
   LONGLONG m_llVolumeTotalSpace;

m_pwszVolumeName: A null-terminated character string that contains the volume mount name of the volume.

m_pwszVolumeDisplayName: A null-terminated character string that contains one of the mount point paths for the volume. If the volume has no mount points, the string MUST be equal to m_pwszVolumeName.

m_llVolumeFreeSpace: The amount of free space, in BYTEs, on the volume.

m_llVolumeTotalSpace: The total size, in BYTEs, of the volume.