1. A computer implemented method for scaling energy use in a virtualized data processing environment, the computer implemented method comprising: configuring a set of PIOAs such that each PIOAs in the set of PIOAs is a functional equivalent of another PIOAs in the set of PIOAs; measuring a utilization of each PIOA in the set of PIOAs; determining a number of PIOAs needed to service a workload; powering down a first subset of PIOAs from the set of PIOAs if the number of PIOAs needed to service the workload is smaller than a number of operational PIOAs; and transferring the I/O operations associated with the first subset of PIOAs to a second subset of PIOAs remaining operational in the set of PIOAs.