Method and system for reliable remote-mirror resynchronization in disk arrays and other mass storage devices
US7340572B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 6, 2002 |
| Grant date | Mar 4, 2008 |
| Priority date | — |
| Expiry date | Nov 29, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/2082
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
On a dominant logical unit provided by a mass-storage device, hot spare disks are employed to create a much larger, disk-based time-ordered WRITE-request buffer that spans, in one embodiment, both electronic memory and hot spare disks. The much larger time-ordered WRITE-request buffer in the modified dominant logical unit allows for storing WRITE requests in time order for a much longer period of time during communications failure between the dominant logical unit and remote-mirror logical unit than in the current techniques that employ only an electronic-memory-based time-ordered WRITE-request buffer. On the remote-mirror logical unit, mass-storage space is provided for an alternate logical unit that can be resynchronized with the dominant logical unit following restoration of communications between the dominant logical unit and remote-mirror logical unit. When resynchronization is complete, a simple logical-unit-pointer switch operation can be employed to designate the alternate logical unit as the new remote-mirror logical unit, and the previous remote-mirror logical unit as the alternate logical unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.