Comment 8 for bug 1469179

After some testing setting root_gb to zero in build_request_spec function which is the function creating the request spec it doesn't seem like this affects the data that is inserted into the nova database which will still lead to the resource tracker, scheduling and horizon etc showing the wrong used disk. We need to find a good way to 1) check if a booted instance has a cinder root volume 2) if it has set the root_gb and ephemeral_gb to zero for that instance so that it's not counted against the local used disk space for the compute node which will result in wrong resource tracking and wrong scheduling.