Warm start cache recovery in a dual active controller with cache coherency using stripe locks for implied storage volume reservations
US6490659B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2000 |
| Grant date | Dec 3, 2002 |
| Priority date | — |
| Expiry date | Mar 31, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D10/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A storage volume reservation system and method for maintaining cache coherency amongst a plurality of caching controllers in a data storage system during a warm start cache recovery utilizing a stripe lock data structure. The stripe lock data structure is defined to maintain reservation status of cache lines within data extents that are part of a logical unit or storage volume. A battery backup unit (BBU) stores stripe lock data structure and dirty cache line data of each of the plurality of controllers during a power failure. Using the stripe lock data structure, a delay required for continued processing of I/O requests from one or more host computers following the warm start cache recovery is minimized. Without saving the stripe lock data structure, continued processing of I/O requests from one or more host computers requires reestablishing stripe locks, during the warm start cache recovery, for cache line data saved before the power failure. A computer program product for maintaining cache coherency amongst a plurality of caching storage controllers in a data storage system during a warm start is also provided which includes a computer readable medium and a computer mechanism st…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.