A storage device and a method for scanning a storage medium. A storage medium for storing data in the form of marks is scanned by an array of probes for mark detecting purposes in a scanning mode. The storage medium has fields with each field to be scanned by an associated one of the probes. At least one of the fields has marks representing operational data for operating the scanning mode. Scanning parameters are computed from the operational data and the scanning mode is adjusted according to the computed parameters.