Introduced with the IBM® XIV® Storage System software v11.5, the multi-site mirroring function, also referred to as the 3-way mirroring in the XIV GUI, enables world-class high availability and disaster recovery capabilities. As such, the function also enables clients to comply with business, government, and industry-driven requirements and regulations.

Essentially, 3-way mirroring as implemented in XIV provides you with:

• Three concurrent copies of data
• Simple failover and failback mechanism, while keeping data mirrored to ensure business continuity and guarantees:

– Minimized risk for data outage, service availability, and low business impact in general

– Expedited failover and data restoration in the event of disaster

• Negligible performance impact, by building upon the ultra-efficient, field proven, XIV remote mirroring technology.

This paper describes the 3-way mirroring basic concepts, terminology, and practical usage. It contains several use cases (failover/failback scenarios) for disaster recovery.

3-way mirroring overview

3-way mirroring definition and terminology

3-way mirroring characteristics

Setting up 3-way mirroring

Disaster recovery scenarios with 3-way mirroring