Quantitative Estimation of the Performance Delay with Propagation Effects in Disk Power Savings

The biggest power consumer in data centers is the storage system. Coupled with the fact that disk drives are lowly utilized, disks offer great opportunities for power savings, but any power saving action should be transparent to user traffic. Estimating correctly the performance impact of power saving becomes crucial for the effectiveness of power saving. Here, we develop a methodology that quantitatively estimates the performance impact due to power savings by taking into consideration the propagation delay effects. Experiments driven by production server traces verify the correctness and efficiency of the proposed analytical methodology.