Patent ID: 8639958

Claim:
A system comprising: a storage subsystem of a data site having multiple storage devices, the devices organized into a hierarchy comprised of at least one disk array and at least one volume; a functional unit in communication with the storage subsystem, the functional unit comprising: a storage device manager to monitor and report power consumption of the storage devices; a data access manager to monitor and report data access performance on each of the storage devices, including the data access manager to store policies of the storage devices; a power manager in communication with the storage device manager and the data access manager to receive the reports, the power manager to employ real-time heuristics to lower power usage of at least one storage device in the subsystem by at least a required amount in response to a request to limit power while maintaining performance responsive to the stored policies, the heuristics comprising: a first heuristic to select one of the devices in one of a selection of tiers in the hierarchy based upon a priority setting, wherein the priority setting includes importance of operability of the selected device, and to lower a power consumption setting of the selected device; and a second heuristic to measure power consumption feedback after the first heuristic lowers the power consumption setting of the selected device based upon the priority setting, and the second heuristic to adjust selection of the devices according to the measured feedback, wherein availability of a device for power consumption setting adjustment is evaluated in the selected tier prior to inter-tier selection of a third device.