internal data and metadata checksumming to detect silent data corruption. In addition, if a corruption is detected and the file system uses integrated RAID mechanisms that provide data redundancy, such file systems can also reconstruct corrupted data in a transparent way. This approach allows improved data integrity protection covering the entire data paths, which is usually known as end-to-end data protection, compared with other data integrity approaches that do not span different layers in the storage stack and allow data corruption to occur while the data passes boundaries between the different layers. Data scrubbing is another method to reduce the likelihood of data corruption, as disk errors are caught and recovered from before multiple errors accumulate and overwhelm the number of parity bits. Instead of parity being checked on each read, the parity is checked during a regular scan of the disk, often done as a low priority background process. Note that the "data scrubbing" operation activates a parity check. If a user simply runs a normal program that reads data from the disk, then the parity would not be checked unless parity-check-on-read was both supported and enabled on the disk subsystem. If appropriate mechanisms are employed to detect and remedy data corruption, data integrity can be maintained. This is particularly important in commercial applications (e.g. banking), where an undetected error could either corrupt a database index or change data to drastically affect an account balance, and in the use of encrypted or compressed data, where a small error can make an extensive dataset unusable. See also Various resources: Data degradation, also called data rot Computer science Data integrity Database integrity Radiation hardening Software rot, also called bit rot Countermeasures: Data Integrity Field ECC memory Forward error correction List of data recovery software Parchive RAID Reed–Solomon error correction References External links SoftECC: A System for Software Memory Integrity Checking A Tunable, Software-based DRAM Error Detection and Correction Library for HPC Detection and Correction of Silent Data Corruption for Large-Scale High-Performance Computing End-to-end Data Integrity for File Systems: A ZFS Case Study DRAM Errors in the Wild: A Large-Scale Field Study A study on silent corruptions, and an associated paper on data integrity (CERN, 2007) End-to-end Data Protection in SAS and Fibre Channel Hard Disk Drives (HGST) Data quality Product expiration