| 摘要 |
A two-dimensional parity method and system that provides three-disk fault tolerance in an array of disks, such as a RAID system, is presented. The method includes arranging strips containing data in the disk array into horizontal and diagonal parity sets, each parity set including at least one data strip as a member and no single data strip is repeated in any one parity set. The diagonal parity sets are then grouped into two groups of diagonal parity sets-Group 1 and Group 2-such that each data strip is a member of a unique diagonal parity set in Group 1 and a unique diagonal parity set in Group 2. Horizontal XOR parities are calculated and stored in a designated disk. Diagonal XOR parities are calculated and at least some of the diagonal XOR parities are stored in a designated disk. The remaining diagonal parities are stored in a diagonal parity stripe so that diagonal parity can be retrieved in the event of a disk failure.
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