Did You Know...
...Chester Carlson was a patent agent who tired of having to make multiple copies of patent applications using the only duplication method available at the time: carbon paper. In 1959 he came up with a new copying system and took it to IBM for evaluation. The "experts" at IBM determined potential sales to be only 5,000 units because people wouldn't want to use a bulky machine when they had carbon paper. Carlson's invention was the xerography process, the company founded on the system is Xerox.
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US Patent 5331646 - Error correcting code technique for improving reliablility of a disk array
US Patent Issued on July 19, 1994
Estimated Patent Expiration Date:
May 8, 2012Estimated 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.
Estimated Patent Expiration Date:
May 8, 2012Estimated 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.AbstractAn array of disk drives organized as a data storage system including n parity drives forming n parity chains where each parity drive maintains the parity bits of a different combination of data drives and each data drive is included in at least two parity chains, and where no two data drives are associated with the same combination of parity chains. The present ECC technique requires only n parity drives for up to 2n -n-1 data drives for a maximum total of 2n -1 disk drives. Each data drive is included in two or more parity chains and each parity chain is unique. The n parity drives are taken two at a time, then three at a time, and so on up to n at a time, each combination being unique, until all of the data drives are associated with parity chains. The ECC technique is implemented using a disk controller which is coupled to the array of disk drives and constantly maintains the parity information on the parity drives. The disk controller selects appropriate parity chains to reconstruct the data of any two data drives that fail, and also performs the reconstruction onto replacement disk drives. Data striping or distribution of the data and parity information on the disk drives further increases the performance of a disk array using the present ECC technique.Other References
| InventorsAssigneeApplicationNo. 880724 filed on 05/08/1992US Classes:714/766, Check bits stored in separate area of memory714/6, Redundant stored data accessed (e.g., duplicated data, error correction coded data, or other parity-type data)714/7, Reconfiguration (e.g., adding a replacement storage component)714/770Disk arrayExaminersPrimary: Baker, Stephen M.Attorney, Agent or FirmUS Patent References4958351, High capacity multiple-disk storage method and apparatus having unusually high fault tolerance level and high bandpassIssued on: 09/18/1990 Inventor: Flora, et al.5134619, Failure-tolerant mass storage system Issued on: 07/28/1992 Inventor: Henson, et al.5148432, Arrayed disk drive system and method Issued on: 09/15/1992 Inventor: Gordon, et al.5265098, Method and means for managing DASD array accesses when operating in degraded mode Issued on: 11/23/1993 Inventor: Mattson, et al.5265104, Data storage system including redundant storage devices Issued on: 11/23/1993 Inventor: Weng5271012Method and means for encoding and rebuilding data contents of up to two unavailable DASDs in an array of DASDs Issued on: 12/14/1993 Inventor: Blaum, et al. International ClassesG06F 011/10G06F 011/20 G11B 020/18 |
