Comment 3 for bug 1825020

Hmm, even by passing the root_bdm to _validate_flavor_image_nostatus it can fail with VolumeSmallerThanMinDisk if the volume_size is smaller than the min_disk size of the backing image.

I think the original intent behind passing root_bdm=None to _validate_flavor_image_nostatus during resize was to just side-step these disk size checks for volume-backed servers but that doesn't seem to be easy without passing some parameter to _validate_flavor_image_nostatus to just tell it to ignore size checks.