Bad Sector
A disk sector that cannot be used for data storage, usually because of media damage or imperfections. Finding, marking, and avoiding bad sectors on a disk is one of the many tasks performed by a computer’s operating system. A disk-formatting utility can also find and mark the bad sectors on a disk.
A bad sector is the result of mechanical damage, most commonly caused by a head crash, manufacturing flaw(s), wear-and-tear, physical shock, sudden power outages, or dust intrusion. Bad sectors are a threat to information security in the sense of data remanence. Very often physical damages can interfere with parts of many different files.
Bad sectors may be detected by the operating system or the disk controller. Most file systems contain provisions for sectors to be marked as bad, so that the operating system avoids them in the future. Disk diagnostic utilities, such as CHKDSK (Microsoft Windows), Disk Utility (on macOS), or badblocks (on Linux) can actively look for bad sectors upon user request.
⠀ Dictionary of computer and Internet terms / Douglas A. Downing, Michael A. Covington, Melody Mauldin Covington. — 10th ed. – 561 c. – 59