System and method for improved rebuild in RAID
US8751861B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 2012 |
| Grant date | Jun 10, 2014 |
| Priority date | — |
| Expiry date | Nov 30, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1092
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present disclosure is a system and method for improved RAID rebuilds under host IO conditions, that greatly improves rebuild times and prevents host IO starvation. A queue in a drive that is part of the RAID is used to store rebuild and host IO requests, with rebuild IOs issued to the head of the drive queue. Rebuild requests in the drive are delayed by a delay time. This delay ensures there is no unintended side effect of this invention that may result in host IO starvation for the RAID system. Delay is computed as a heuristic function from a plurality of variables, such as disk head response times, time allotted for rebuild, number of rebuild threads, drive behavior, rebuild IO profile, host IO profile including workload and locality, and a timeline of sequenced events, which in one preferred embodiment cycles every 70 seconds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.