A method for controlling a storage apparatus connectable to a server, the storage apparatus including a first storage area and a second storage area for storing data, the method comprises: copying the data stored in the first storage area into the second storage area; copying data stored in the location of the first storage area addressed by the command to be accessed by the server into the location of the second storage area before execution of the command when the storage apparatus receives a command for accessing data stored in a location of either of the first storage area and second storage area from the server; and executing the command for accessing at least one of the location in the first storage area and the corresponding location in the second storage area.