2.2.1.3.2 VolumeGUID Generation
VolumeGUIDs (Volume Globally Unique Identifiers, or volume identifiers, see also [MS-DTYP] section 2.3.4) are generated on SMB servers. The generation of VolumeGUIDs MUST satisfy the following constraints:
The VolumeGUID MUST be a 128-bit opaque value.
The VolumeGUID MUST be unique for a logical file system volume on a given server.
The VolumeGUID for the volume can change while the system is running. The VolumeGUID can change when the system is restarted.
All possible values for the VolumeGUID are valid.