A method, system, and computer program product for controlling data center cooling. In an example embodiment the method includes calculating, using a processor, an over-provisioning factor, where the over-provisioning factor is a function of a ratio of a rated cooling power to a calculated cooling power of a set of cooling units, the set of cooing units comprising at least one cooling unit. The method proceeds by adjusting the data-center cooling until the over-provisioning factor is substantially equal to a target over-provisioning factor.