A cooperative asynchronous write mechanism for NAS

Network Attached Storage (NAS) is the high performance storage appliance that provides shared data to clients and other servers in a Local Area Network (LAN). The existing NAS products provide file services by themselves. They can not cooperate with each other to improve performance. This paper presents an automatically cooperative asynchronous write mechanism for NAS: ACAWM. ACAWM is a set of pure software mechanisms which provide both the reliability of synchronous write operations and the performance of asynchronous write operations. ACAWM contains two parts: automatically cooperative mechanism and asynchronous write mechanism. The automatically cooperative mechanism of ACAWM can make all NAS in a LAN to cooperate with each other without artificial configuration. Basing on the automatically cooperative mechanism, asynchronous write mechanism of ACAWM can allow a NAS to use the free RAM of the cooperative NAS to realize asynchronous write in the file system of NAS. The data of asynchronous write in ACAWM are saved on both of the two cooperative NAS before being written to disk, thus ACAWM can ensure the security of data. The design of ACAWM fully considers the usability of NAS and has no special requirement for the system software of clients. The experiments in this paper prove that ACAWM can greatly improve the performance of NAS.