Remote mirroring system, device, and method
US6671705B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1999 |
| Grant date | Dec 30, 2003 |
| Priority date | — |
| Expiry date | Aug 17, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99955
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a remote mirroring system, device, and method, a master storage unit stores information in a log and uses the information from the log to quickly resynchronize slave images following a failure in the master storage unit. Upon receiving a write request from a host, the master storage unit stores a write entry in the log. The write entry includes information that identifies a portion of the slave images that may be unsychronized from the master image due to the write request. The master storage unit then proceeds to update the master image and the slave images. The log is preserved through the failure, such that the log is available to the master storage unit upon recovery from the failure. When the master storage unit is operational following the failure, the master storage unit resynchronizes the slave images to the master image by copying those portions of the master image indicated in the log to the slave images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.