Method and means for distributed sparing in DASD arrays
Patent 5258984 Issued on November 2, 1993. Estimated Expiration Date: 
June 13, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
June 13, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesNon-volatile memory storage of write operation identifier in data sotrage device On-line reconstruction of a failed redundant array system Patent #: 5208813 InventorsApplicationNo. 714969 filed on 06/13/1991US Classes:714/7, Reconfiguration (e.g., adding a replacement storage component)714/710Replacement of memory spare location, portion, or segmentExaminersPrimary: Canney, Vincent P.Attorney, Agent or FirmInternational ClassG06F 011/20AbstractA method and means in which data and parity blocks forming parity groups together with spare blocks are distributed over array block locations according to at least one combinatorial design, each group having N data and P parity blocks. The combinatorial designs yield uniform or balanced loading thereby minimizing the number of accesses to reconstruct missing data and parity blocks and their copyback into spare block locations, and, minimize the number of accesses to the reconstructed data referenced subsequent to its copyback. Distributions of the spare block capacity of one or two DASDs are shown over single and multiple arrays and shared among multiple arrays. Parity block distribution although ancillary to spare distribution enhances throughput and reduces the number of accesses for rebuild etc. | |
