Did You Know...
...that it was melting ice cream that inspired the invention of the outboard motor? It was a lovely August day and Ole Evinrude was rowing his boat to his favorite island picnic spot. As he rowed, he watched his ice cream melt and wished he had a faster way to get to the island. At that moment the idea for the outboard motor was born!
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US Patent 6282671 - Method and system for improved efficiency of parity calculation in RAID system
US Patent Issued on August 28, 2001
Estimated Patent Expiration Date:
November 10, 2018Estimated 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:
November 10, 2018Estimated 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.AbstractThe method and system for improved efficiency and parity calculation in RAID data storage system. RAID data storage systems permit recovery of data in the event of a drive failure by storing a parity value for each stripe of data on a separate drive. Each time data is written to a RAID data storage the parity value for the associated data stripe must be updated. Parity may be calculated utilizing two different algorithms. New parity may be calculated utilizing the old data value, the new data value and the old parity value, or calculated utilizing the new data value and all remaining old data within the associated data stripe. The number of input/output operations required to calculate parity utilizing each algorithm is predetermined and the method requiring the least number of input/output operations is selected, unless data sequentiality is detected. If sequential data is present the parity value is calculated utilizing the new data and all old data in the associated data stripe, even if a greater number of input/output operations are initially required, as further sequential input/output operations will be more efficient. | InventorsApplicationNo. 189689 filed on 11/10/1998US Classes:714/6, Redundant stored data accessed (e.g., duplicated data, error correction coded data, or other parity-type data)711/114Arrayed (e.g., RAIDs)Field of Search714/6, Redundant stored data accessed (e.g., duplicated data, error correction coded data, or other parity-type data)714/801, Parity generator or checker circuit detail714/766, Check bits stored in separate area of memory711/143, Write-back711/113, Caching711/114, Arrayed (e.g., RAIDs)711/155Read-modify-write (RMW)ExaminersPrimary: Ray, Gopal C.Attorney, Agent or FirmUS Patent References3905023, 5315602, Optimized stripe detection for redundant arrays of disk drivesIssued on: 05/24/1994 Inventor: Noya, et al.5572660, System and method for selective write-back caching within a disk array subsystem Issued on: 11/05/1996 Inventor: Jones5594862, XOR controller for a storage subsystem Issued on: 01/14/1997 Inventor: Winkler, et al.5794069Information handling system using default status conditions for transfer of data blocks Issued on: 08/11/1998 Inventor: Chisholm, et al. International ClassesG06F 011/10H03M 013/00 |
