Method and system for managing metadata for a plurality of storage platforms that provide virtualization services is provided. The magnetization free layer 1 includes a magnetization switching region 13, a first magnetization fixed region 11 and a second magnetization fixed region 12. The computer program is modified such that it utilizes the dummy service. The reference-voltage generating circuit 119 comprises an n-type MOS transistor 111, a bipolar transistor 112 which determines the drain voltage of the n-type MOS transistor 111, and a control circuit 120 for controlling the drain current of the n-type MOS transistor 111. The power supply system may additionally include at least one load having load input terminals, wherein the load input terminals may be in electrical communication with the isolation transformer output terminals of the one or more isolation transformers.