Append-only storage in a disk array using striping and parity caching
US5860090A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 20, 1995 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Oct 20, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2211/1009
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer writes information to a series of blocks that form a stripe on a disk array. The computer first checks if the stripe contains data written in a current pass. If the stripe has stored data, but is not completely full, the computer calculates a parity for the stripe (assuming the information is appended to the data). If appending the information to the data would not complete the stripe, the computer caches the parity outside the disk array. The computer appends the information to the data and updates a parity block on the stripe each time information is appended to the stripe. In various implementations, the computer places a stamp on the pages forming the blocks in the stripe to which information is written. Alternatively, the computer zeroes the bits in the remaining blocks to form a complete stripe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.