Disk-less quorum device for a clustered storage system
US7827441B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 30, 2007 |
| Grant date | Nov 2, 2010 |
| Priority date | — |
| Expiry date | Oct 24, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2211/1057
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A disk-less quorum device in a clustered storage system includes non-volatile memory to store status information regarding the cluster and each storage controller in the cluster. The quorum device maintains a bitmap, shared by the controllers in the cluster, in the non-volatile memory. The bitmap indicates the status of a write operation to any data block or parity block. A “dirty” data unit in the bitmap indicates that a write operation has been submitted but is not yet finished. Upon submitting a write request (to update a data block or a parity block) to the storage facility, a controller sets the corresponding data unit “dirty” in the bitmap. After receiving an acknowledgement from the storage facility indicating that the operation has been completed, the controller clears the corresponding data unit. If a controller fails during a write operation, another controller can use the bitmap to re-establish data consistency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.