Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Data redundancy means that some data is stored twice, or that some data can be derived from other data. An advantage is that errors can be detected, and that when a data set with some redundancy is damaged, it may be possible to more or less reconstruct the original data. Thus redu ...Full description
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Data redundancy means that some data is stored twice, or that some data can be derived from other data. An advantage is that errors can be detected, and that when a data set with some redundancy is damaged, it may be possible to more or less reconstruct the original data. Thus redundancy can be useful in computer data storage, and is a property of some disk arrays (most commonly in RAID systems) which provides fault tolerance, so that all or part of the data stored in the array can be recovered in the case of disk failure. The cost typically associated with providing this feature is a reduction of storage capacity available to the user, since the implementations require either a duplication of the entire data set, or an error-correcting code to be stored on the array.