Method for storing parity and rebuilding data contents of failed disks in an external storage subsystem and apparatus thereof
US6158017A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1998 |
| Grant date | Dec 5, 2000 |
| Priority date | — |
| Expiry date | Mar 16, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/6561
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method for storing parity and rebuilding the data contents of two failed disks in an external storage subsystem comprises the steps of: proving a disk array defined as a matrix of (N-1).sup.* N including N disks each logically divided into N-1 data blocks where N is a prime number, the data blocks of a row being defined as a horizontal parity group, the data blocks existing in a rightwardly and upwardly continuous diagonal line being defined as a diagonal parity group; defining the data blocks existing in the diagonal line leftwardly and downwardly from the first data block of the (N-1) disk to the last data block of the first disk as horizontal parity blocks; defining the data blocks existing in the (N-1) row of the matrix as diagonal parity blocks; exclusive OR'ing (XORing) the contents of each of the horizontal and diagonal parity groups to obtain the parity value stored into the parity block of the corresponding horizontal or diagonal parity group; and analyzing a diagonal parity group including an error data block of the two failed disks to restore the error data block and then, the horizontal parity group including the restored error data block to restore another error data…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.