One aspect of the invention is a method for backing up data. A recording speed to be used for recording on an individual one of the at least two recording layers is selected based on a maximum radiation power specified for the recording operation, and the speed of the recording operation is controlled individually for each of the at least two layers based on the selected recording speed. A plurality of contacts received in the insulated housing and connected to wires. Side plates with rearward ends are attached to the vertical rails adjacent to the lower rail. Each of the terminals has at least one shoulder to enhance the structural strength thereof.