@classmethod
def _get_sensors_drive(cls, system):
    """Get storage drive sensors reading.

        :param chassis: Redfish `system` object
        :returns: returns a dict of sensor data.
        """
    sensors = {}
    for storage in system.simple_storage.get_members():
        for drive in storage.devices:
            sensor = cls._sensor2dict(drive, 'name', 'model', 'capacity_bytes')
            sensor.update(cls._sensor2dict(drive.status, 'state', 'health'))
            unique_name = '%s:%s@%s' % (drive.name, storage.identity,
                system.identity)
            sensors[unique_name] = sensor
    return sensors
