'Detach volume storage to VM instance.'

def detach_volume(self, connection_info, instance):

    driver_type = connection_info['driver_volume_type']
    LOG.debug('Volume    detach.    Driver    type:    %s', driver_type, instance=instance)
    if (driver_type == constants.DISK_FORMAT_VMDK):
        self._detach_volume_vmdk(connection_info, instance)
    elif (driver_type == constants.DISK_FORMAT_ISCSI):
        self._detach_volume_iscsi(connection_info, instance)
    else:
        raise exception.VolumeDriverNotFound(driver_type=driver_type)
