Detection of defective media in disks

Abstract

The authors present new improved methods for detecting latent sector faults in a disk subsystem as caused by media deterioration of the disk magnetic storage material. Usually, sectors in a disk are accessed using uneven patterns causing some of the sectors to be accessed only seldom. In case of media deterioration on the rarely accessed sectors, a latent disk fault may remain undetected for a long time. To detect latent sector faults, a disk is scanned through periodically. An adaptive algorithm is proposed to utilize the idle time for the disk for scanning commonly used disks that comply with SCSI-II interface standards.