Comment 2 for bug 1054163

So here is what seems to be happening:

1) A non-admin user boots the image in question, caching it on the nova-compute node (by uuid)
2) That non-admin user deletes said image - the image is *not* removed from the cache, however
3) An admin user can still see the metadata in Glance, and since the data is cached locally, it is still bootable by that admin user

It is key to realize that Glance allows admin users to make HEAD (metadata-only) requests of images through the v1 API. When Nova checks for image existence before trying to boot the vm and everything seems to check out. It doesnt attempt to download the data since it has a local cached copy.

I tried creating a new vm from an image that had never been cached and the vm did go to ERROR.