A storage system includes a storage device that includes a storage medium, and a control device that is connected to an upstream-side device, scans the storage device, writes the data in the storage device, and reads the data from the storage device, wherein the control device determines whether or not the data is being written in or read from the storage device, wherein when the data is being written or read, the control device scans the storage medium at intervals of a first time in a first direction that is either a direction in ascending order of logical block addresses of the storage medium or a direction in descending order of the logical block addresses of the storage medium, and wherein when the data is not written and read during the time period, the storage device scans the storage medium in a second direction.