bad sector mapping

A bad sector is a faulty sector on a hard disk or flash memory that cannot be written to or whose data cannot be accessed.

Under Windows, such sectors can be detected by utilities such as Check Disk (CHKDSK) or Scan Disk (SCANDISK).

Under Unix it is Badblocks. The detected bad sectors can be marked as unusable and are then skipped by the operating system. So that the data is stored in another sector. The marking of bad sectors is called Bad Sector Mapping. If only the shifting of the sector takes place within the same track, one speaks of sector slipping.