Reference magnetic elements or bits with a range of magnetic volumes smaller than the minimum size used for actual data storage are written or patterned in the data storage device. The reference elements or bits have dimensions such that their magnetization will relax in a shorter time than that of the minimum expected relaxation time of the storage elements or bits. Probing of the magnetization of the reference elements or bits allows the detection of the probable onset of magnetization relaxation in the storage elements or bits therefore signaling that the re-writing (re-magnetizing) of the storage elements or bits is necessary. Such a scheme can be organized over rows, columns, or sectors.