公开(公告)号：US20170220249A1

公开(公告)日：2017-08-03

申请号：US15011050

申请日：2016-01-29

Applicant: NetApp, Inc.

Inventor： Mahmoud K. Jibbe ,  Jeff Hudson ,  Joseph Blount ,  Keith Holt

IPC: G06F3/06 ,  G06F12/08

CPC classification number: G06F12/0806 ,  G06F11/0727 ,  G06F11/1076 ,  G06F11/20 ,  G06F2212/621

Abstract: Embodiments of the present disclosure enable high availability and performance in view of storage controller failure. A storage system includes three or more controllers that may be distributed in a plurality of enclosures. The controllers are in high availability pairs on a per volume basis, with volumes and corresponding mirror targets distributed throughout the storage system. When a controller fails, other controllers in the system detect the failure and assess whether one or more volumes and/or mirror targets are affected. If no volumes/mirror targets are affected, then write-back caching continues. If volume ownership is affected, then a new volume owner is selected so that write-back caching may continue. If mirror target ownership is affected, then a new mirror target is selected so that write-back caching may continue. As a result, write-back caching availability is increased to provide low latency and high throughput in degraded mode as in other modes.