Methods and apparatus for balancing loads on a storage subsystem among a plurality of controllers
US6108684A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1996 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Dec 23, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/505
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods and associated apparatus for balancing the I/O request processing load within a plurality of controllers in a storage subsystem. The methods of the present invention are operable within interconnected controllers of a storage subsystem to shift the processing of received I/O requests to less loaded controllers and to do so in a manner transparent to legacy attached host systems. In a first embodiment of the present invention referred to as back-end load balancing, I/O requests are transferred from a first controller, to which the I/O request was directed by the attached host system, to a second controller for further processing. In this back-end load balancing embodiment, all write data associated with a write request as well as returned information including status or read data, is exchanged between the first and second controllers such that the first controller performs all communication with the attached host system. In a second embodiment referred to as front-end load balancing, the first controller receives an I/O request and transfers the request of a second controller. The second controller then completes the I/O request including any requisite communication with the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.