iSER Storage Target for Object-Based Storage Devices

Abstract

In order to increase client capacity and performance, storage systems have begun to utilize the advantages offered by modern interconnects. Previously storage has been transported over costly fibre channel networks or ubiquitous but low performance Ethernet networks. However, with the adoption of the iSCSI extensions for RDMA (iSER) it is now possible to use RDMA based interconnects for storage while leveraging existing iSCSI tools and deployments. Building on previous work with an object-based storage device emulator using the iSCSI transport, we extend its functionality to include iSER. Using an RDMA transport brings with it many design issues including the need register memory to be used by the network, and how to bridge the quite different RDMA completion semantics with existing event management based on file descriptors. Experiments demonstrate reduced latency and greatly increased throughput compared to iSCSI implementations both on gigabit ethernet and on IP over InfiniBand.