Method and apparatus for providing battery-backed immediate write back cache for an array of disk drives in a computer system
US6438647B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 2000 |
| Grant date | Aug 20, 2002 |
| Priority date | — |
| Expiry date | Sep 18, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0866
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method and apparatus for providing battery-backed immediate write back cache for an array of disk drives in a computer system. Cooperation between a new replacement controller and a survivor controller is enabled so that write back cache operation can start immediately, and not be dependant on the battery condition in the replacement controller. Protection of the data through a single point of failure is maintained. When a controller fails, a replacement controller is installed and battery state information is exchanged. If any battery backup meets a predetermined threshold, all of the controllers run in the write back cache mode. However, if not one of the battery backups meets a predetermined threshold, all of the controllers run in the write through cache mode. Thus, the system does not need to wait for a replacement controller's battery backup to be reconditioned before the higher speed write back cache is used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.