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A hard disk drive failure occurs when a hard disk drive malfunctions and the stored information cannot be accessed with a properly configured computer. A hard disk failure may occur in the course of normal operation, or due to an external factor such as exposure to fire or water or high magnetic fields , or suffering a sharp impact or ...
Many errors are detected and corrected by the hard disk drives using the ECC codes [17] which are stored on disk for each sector. If the disk drive detects multiple read errors on a sector it may make a copy of the failing sector on another part of the disk, by remapping the failed sector of the disk to a spare sector without the involvement of ...
In the normal operation of a hard drive, the detection and remapping of bad sectors should take place in a manner transparent to the rest of the system and in advance before data is lost. There are two types of remapping by disk hardware: P-LIST (mapping during factory production tests) and G-LIST (mapping during consumer usage by disk microcode).
Hard disk and other storage drives are subject to failures (see hard disk drive failure) which can be classified into two basic classes: Predictable failures which result from slow processes such as mechanical wear and gradual degradation of storage surfaces. Monitoring can determine when such failures are becoming more likely.
Internal hard drive defect management is a system present in hard drives for handling of bad sectors.The systems are generally proprietary and vary from manufacturer to manufacturer, but typically consist of a "P" (for "permanent" or "primary") list of bad sectors detected in the manufacturing stage and a "G" (for "growth") list of bad sectors that crop up after manufacturing. [1]
A wide variety of failures can cause physical damage to storage media, which may result from human errors and natural disasters. CD-ROMs can have their metallic substrate or dye layer scratched off; hard disks can suffer from a multitude of mechanical failures, such as head crashes, PCB failure, and failed motors; tapes can simply break.
Most disk, disk controller and higher-level systems are subject to a slight chance of unrecoverable failure. With ever-growing disk capacities, file sizes, and increases in the amount of data stored on a disk, the likelihood of the occurrence of data decay and other forms of uncorrected and undetected data corruption increases. [18]
The worst type of errors are silent data corruptions which are errors undetected by the disk firmware or the host operating system; some of these errors may be caused by hard disk drive malfunctions while others originate elsewhere in the connection between the drive and the host. [74]