Method and system for using shared memory with optimized data flow to improve input/output throughout and latency

Abstract

The data path in a network storage system is streamlined by sharing a memory among multiple functional modules (e.g., N-module and D-module) of a storage server that facilitates symmetric access to data from multiple clients. The shared memory stores data from clients or storage devices to facilitate communication of data between clients and storage devices and/or between functional modules, and reduces redundant copies necessary for data transport. It reduces latency and improves throughput efficiencies by minimizing data copies and using hardware assisted mechanisms such as DMA directly from host bus adapters over an interconnection, e.g. switched PCI-e 'network'. This scheme is well suited for a 'SAN array' architecture, but also can be applied to NAS protocols or in a unified protocol-agnostic storage system. The storage system can provide a range of configurations ranging from dual module to many modules with redundant switched fabrics for I/O, CPU, memory, and disk connectivity.