'Provide a default root device name for the driver.
:param nova.objects.instance.Instance instance:
The instance to get the root device for.
:param nova.objects.ImageMeta image_meta:
The metadata of the image of the instance.
:param nova.objects.BlockDeviceMapping root_bdm:
The description of the root device.'

def default_root_device_name(self, instance, image_meta, root_bdm):

    raise NotImplementedError()
