A storage management module for evaluating and repairing errors during monitoring or testing of storage devices of a storage system is described herein. When a storage device exhibits errors that reaches (in number) an error threshold, the storage management module determines whether any errors are due to damaged sectors localized in a single physical area of a predetermined size (referred to as a “patch”) of a platter of the storage device using the physical addresses of the errors. Two or more errors may be grouped as a single error if they are located within a predetermined threshold distance from each other on a platter and counted as a single error against the error threshold. A patch containing two or more damaged sectors is referred to as a “damaged” patch. In some embodiments, all sectors of a damaged patch (including undamaged sectors) are reassigned to spare sectors.