Efficient variable-block data storage system employing a staggered fixed-block-architecture array
US5459853A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1992 |
| Grant date | Oct 17, 1995 |
| Priority date | — |
| Expiry date | Nov 23, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1258
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for operating a synchronized array of fixed block (FBA) formatted Direct Access Storage Devices (DASDs) to store and update variable-length (CKD) formatted records. This method is suitable for use with DASDs that obtain high recording density by using read and write head technology requiring "micro-jogging" to adjust for differing read and write head alignment or banded disk architecture having a higher block count in the outer tracks than in the inner tracks. Magneto-resistive heads may require micro-jogging to realign the write head for recording after reading the physical track location. The invention employs a DASD staggered array architecture having logical tracks consisting of diagonal-major sequences of consecutive blocks arranged in a predetermined wrap-around manner such as a topological cylinder or torus. The minimum necessary number of DASDs (N) in the staggered array is limited by the fixed block size (B), the interblock gap size (G), the average DASD data transfer rate (D), and the micro-jog delay time (T). A (N+1).sup.th DASD may be added to record the parity of each diagonal-major sequence for improved fault-tolerance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.