Use of rdma to access non-volatile solid-state memory in a network storage system

Abstract

A network storage controller uses a non-volatile solid-state memory (NVSSM) subsystem which includes raw flash memory as stable storage for data, and uses remote direct memory access (RDMA) to access the NVSSM subsystem, including to access the flash memory. Storage of data in the NVSSM subsystem is controlled by an external storage operating system in the storage controller. The storage operating system uses scatter-gather lists to specify the RDMA read and write operations. Multiple client-initiated reads or writes can be combined in the storage controller into a single RDMA read or write, respectively, which can then be decomposed and executed as multiple reads or writes, respectively, in the NVSSM subsystem. Memory accesses generated by a single RDMA read or write may be directed to different memory devices in the NVSSM subsystem, which may include different forms of non-volatile solid-state memory.

1 . A method comprising:
 using a first memory within a network storage controller to temporarily store data in response to requests from one or more clients of the network storage controller;   using a non-volatile solid-state memory as stable storage to store data written in response to one or more of the requests persistently; and   using remote direct memory access (RDMA) controlled by the network storage controller to transfer data between the first memory and the non-volatile solid-state memory, including using RDMA controlled by the network storage controller to read data from the non-volatile solid-state memory.   
     
     
         2 - 51 . (canceled)