Distributed Storage Cluster Design for Remote Mirroring Based on Storage Area Network

With the explosion ofinformation nowadays, applying data storage safety requirements hasbecome a new challenge, especially in high data available clusterenvironments. With the emergence of Storage Area Networks (SANs),storage can be network-based and consolidated, and mass datamovements via Fiber Channels (FCs) can be of very high speed. Basedon these features, this paper introduces a dual-node storage clusterdesigned for remote mirroring as a concurrent data replicationmethod to protect data during system failures. This design takesfull advantage of a SAN system's benefits, and it adopts asynchronous protocol to guarantee a fully up-to-date data copy onthe remote site. By developing a Linux kernel module to control theI/O flow and by using the technologies of software Logic UnitNumber (LUN) masking, background online resynchronization and aself-management daemon, we have achieved a reliable mirroring systemwith the characteristics of server-free data replication, faulttolerance, online disaster recovery and high performance. In thisstudy, we implemented the design in a remote mirror subsystem builton a software Fiber Channel Storage Area Network (FC-SAN) system.