Patent ID: 8140754

Claim:
A computerized data storage system comprising: a top tier storage apparatus; and a second tier storage apparatus, connected to the top tier storage apparatus, the second tier storage apparatus comprising one or more hard disk drives operable to store data organized into one or more second tier logical volumes, wherein the top tier storage apparatus is operable to: map the one or more second tier logical volumes to one or more top tier logical volumes; create a map of a correspondence of the top tier logical volumes to the second tier logical volumes and power boundary information from the second tier storage apparatus; and identify whether the second tier storage apparatus has a self spin-down capability; wherein if the second tier storage apparatus does not have the self spin-down capability, send a command to instruct the second tier storage apparatus to spin down one or more of the hard disk drives of the second tier storage apparatus corresponding to one or more logical data volumes; and wherein if the second tier storage apparatus has the self-spin-down capability, the second tier storage apparatus checks if all volumes in a parity group have “spin-down” status, wherein if said all volumes in the parity group have the “spin-down” status, the second tier storage apparatus is operable to spin-down all HDDs in the parity group.