Non-write-back mirror image and direct write switching method for cache mirror image system

Abstract

The invention provides a non-write-back mirror image and direct write switching method for a cache mirror image system. The method includes: setting a double-controller storage system. The double-controller storage system at least comprises two controllers. Each controller supports mirror image cache, write mirror image and direct write modes, supports write mirror image mode and direct write mode switching, and does not support a write back mode. When the double controllers are at the write mirror image mode, when one of the controllers fails, backup data can be obtained from the other controller, and data reliability can be guaranteed. When only one control is remained, and the survived controller can be perform write mirror image mode and direct write mode switching. Compared with the prior art, the method high in practicality has the advantages that the write-back mode is abandoned through switching of write mirror image and direct write strategies, disk failure can be avoided, and reliability of the storage system can be guaranteed.

Description

technical field [0001] The invention relates to the technical field of communication information, in particular to a non-write-back mirroring and direct-writing switching method of a cache mirroring system. Background technique [0002] Cache mirroring technology is a solution for data loss in the cache that may occur when storage processing fails. It saves cached data on two controllers at the same time, and automatically backs up the end controller when the system is working. It is a commonly used cache protection technology in a dual-controller storage system. Its basic principle is to establish a cache mirror on each controller to ensure cache consistency between the dual controllers. [0003] In a storage system that supports cache mirroring, in addition to the traditional write-back (WRITE_BACK) and write-through (WRITE_THROUGH) modes, a write-mirror (WRITE_MIRROR) mode needs to be added to support the establishment of cache mirroring. [0004] In a dual-controller st...

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Problems solved by technology

[0005] However, in the actual storage system, when the write strategy is switched between each other, when the write mirror and write back are directly switched, due to the low efficiency of direct write, a large amount of data accumulated in the cache cannot be refreshed to the disk, which may cause write timeout, resulting in a crash

[0006] The purpose of the present invention is to provide a non-write-back mirroring and direct-writing switching method, by adding part of the processing in the switching between writing mirroring and direct writing, to solve the problem of disk loss that may be caused, so that the support of the non-writeback mode can be realized Dual-controller storage system with cache mirroring

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