  Cloud users have little visibility into the performance characteristics and
utilization of the physical machines underpinning the virtualized cloud
resources they use. This uncertainty forces users and researchers to reverse
engineer the inner workings of cloud systems in order to understand and
optimize the conditions their applications operate. At Massachusetts Open Cloud
(MOC), as a public cloud operator, we'd like to expose the utilization of our
physical infrastructure to stop this wasteful effort. Mindful that such
exposure can be used maliciously for gaining insight into other users
workloads, in this position paper we argue for the need for an approach that
balances openness of the cloud overall with privacy for each tenant inside of
it. We believe that this approach can be instantiated via a novel combination
of several security and privacy technologies. We discuss the potential
benefits, implications of transparency for cloud systems and users, and
technical challenges/possibilities.
