Hey Sean, Thanks for responding. It sounds like a nova-manage command is the way forward, to avoid editing the DB directly, the operator would then need to ensure no breaches of aggregate requirements. Ill have a look at the nova-mange command you have referenced. We do now have the os_type set on all our provided images, but this doesn’t stop a customer uploading an image without it set. I guess that’s where a glance image plugin would come in, can you point me at some documentation for me to have a read around. I don’t like the idea of having to resize, as these aren’t our instances, as we are operating a public cloud. On an aside, out of curiosity, why was the decision to not cascade these types of changes made, is it simply to provide immutability to instances? Rgds Steve.