Comment 4 for bug 1206081

Refreshing my memory for the flow of these images ... http://www.pixelbeat.org/docs/openstack_libvirt_images/

Yes this does seem like a valid issue, though not as serious as the related bug 1177830
as there is only an allocation per image rather than per instance.

Also any sizes over the quote size etc. for an instance wouldn't be thus referenced and so
could be auto deleted at some stage.

But yes this is a valid DOS vector given the difference between input and output sizes.

Now if we did limit sizes, I suppose we could limit to the max flavor size?
But that doesn't help much. One could still upload many small images up to the max flavor size to fill up the _base/

Maybe we need quotas glance side for max actual disk usage per user for all their images?