A storage system wherein a high availability pair is formed with a first volume of a first storage device as a primary volume and a second volume of a second storage device as a secondary volume, an asynchronous copy pair is formed with the first volume as a primary volume and a third volume of a third storage device as a secondary volume, and a standby pair is formed with the second volume as a primary volume and the third volume as a secondary volume. When an asynchronous copy pair formation command is received and a standby pair has not been formed, formation of the asynchronous copy pair is not permitted.
