The Research And Implemetion Of RDMA Technology In Fiber Channel

With the high-speed, low latency, high reliability, transmission distance, and goodscalability features, Fibre Channel becomes the most important Internet technology of thecurrent storage area network (SAN, Storage Area Network).Using RDMA to access data inthe storage network, can effectively prevent multiple copies of data between kernelmemory and user memory, improve the efficiency of the host-side data processing.UsingRDMA technology in Fibre Channel, can combined the both advantages and when appliedto FC-SAN storage network, can effectively reduce network latency, and reduce thehost-side data processing delay, which greatly improve network performance.As for the overall framework of FC-SAN system based on RDMA,research the mainfunctions of all levels included in the system initiator and target,the interface betweenlevels and their interactions,and the process of SCSI commands and data transmission indetail from the initiator to target.Design and implement the SCSI low-level device drivers of Fiber Channel and theRDMA processing layer. Fibre Channel SCSI low-level device drivers has achieved theinteraction with the SCSI mid-layer in Linux kernel; RDMA processing layer hassuccessfully interacted with user-level applications through a virtual character deviceinterface, and realized the FCP protocol, and can drive self-developed Fiber ChannelAdapter to send and receive normal frame, and ultimately can mount remote SCSI storagedevices on the local.Completed the build of a Fiber Channel point to point topology, withthe process of memory registration, mapping reserved memory, receiving and processingthe request from the user-level application, test the read and write performance of accessto the remote SCSI storage devices mounted to local system by RDMA mode, andcompare with the normal mode. The test results show that, the read and write performanceof RDMA mode is superior to the normal mode.