Design and Implementation of an Efficient Multipath for a SAN Environment
Multipath provides multiple paths between application Servers and storage devices. Multipath can overcome single point of failure, and improve a system’s reliability and availability. This paper presents a multi-layer Multipath, and describes the design and implementation of a Multipath system in a storage area network (SAN). For an application server, we implemented Multipath in the volume management layer. For a storage server, we implemented Multipath in the SCSI Middle Level layer. This system can make the most use of the storage server’s characteristics to decrease the time of failure discovery and location, and it is independent of lower SCSI cards and storage devices, so it has good compatibility. This paper also proposes methods for choosing paths, automatically recovering paths and balancing the load. We tested the read performance and the average response time, and the results showed that with the load balanced, the read performance improves 17.9% on average, and the average response time decreases 15.2% on average.
KeywordsLoad Balance Storage Device Application Server Multiple Path Round Robin
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