Method and apparatus for transparent, real time reconstruction of corrupted data in a redundant array data storage system
US5623595A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 26, 1994 |
| Grant date | Apr 22, 1997 |
| Priority date | — |
| Expiry date | Sep 26, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/17336
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for providing transparent, real time reconstruction of corrupted data from a redundant array of storage units in a manner that imposes no performance degradation for reconstruction of such corrupted data and that does not tie up system resources. The present invention is particularly suited to applications in which data is retrieved from storage equipment in approximately equally sized parcels. Each parcel is divided into "N" blocks of data. An "N+1st" parity block for each parcel is derived based on the content of the "N" blocks of data. The "N" blocks of data and the parity block for each parcel are stored in stripes of blocks in a redundancy group consisting of "N+1" data storage units. Data is read from the storage units an entire stripe at a time. To read a stripe, a read request is concurrently sent to each storage unit in the redundancy group, requesting the block of data in that storage unit that corresponds to the stripe being read. Each storage unit independently processes the read request it has received and sends back the requested block as soon as it has been read. As soon as the first "N" blocks are received, they are XOR'd together to reconstru…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.