SUMF: Efficient, Stable, and Reliable SPDK Userspace IO Multipathing Framework

Storage Area Networks (SANs) are critical in enterprise IT infrastructure, offering high-throughput and low-latency storage solutions. However, traditional SAN architectures that rely on kernel-space multipathing software face significant challenges in virtualized environments, where extended IO paths and high context-switching overheads degrade performance. While the Storage Performance Development Kit (SPDK) has emerged as a powerful tool to enhance IO efficiency by enabling userspace drivers, it introduces limitations in multipathing capabilities.To address these challenges, we have developed SUMF (SPDK Userspace IO Multipathing Framework), an innovative userspace IO multipathing software. SUMF leverages SPDK's strengths while overcoming its limitations by directly managing multiple IO paths within virtualized cloud computing environments. This solution reduces IO latency by avoiding unnecessary user-kernel transitions and optimizes the system through improved IO path aggregation and selection, dynamic load balancing, and robust failover and failback mechanisms. Our experiments demonstrate that, compared to native SPDK, SUMF achieves higher throughput and shows stronger adaptability to path failures and bandwidth imbalances during transmission.