【作者】 陈鹏；

【导师】 周功业；

【作者基本信息】 华中科技大学 ， 计算机系统结构， 2007， 硕士

【摘要】 随着计算机技术和网络技术的发展对存储系统提出了越来越高的要求,面向对象存储系统(Object Based storage System,OBS)是适应于下一代互联网环境的新型网络存储技术。OBS由计算节点、对象存储设备(Object-based Storage Device,OSD)、元数据服务器、存储网络四个部分组成。OBS以对象接口为数据访问方式,从而可充分利用数据对象属性来提高存储节点的自治性和主动性,而存储网络是对象存储系统的重要基础设施,其性能对存储系统的整体性能有重大的影响。在网络存储协议HyperSCSI(Hyper Small Computer System Interface)的基础上,为面向对象存储系统设计了一种改进的网络存储协议—可靠加强型小型计算机系统接口协议(Reliable Hyper Small Computer System Interface,RH-SCSI)。HyperSCSI与网络存储协议iSCSI相比,HyperSCSI具有更高的性能。但HyperSCSI也有不足,其错误恢复机制不强,在提高性能的同时可靠性方面有所欠缺,同时在扩展性方面也有限制。针对HyperSCSI的不足,设计的RH-SCSI协议在HyperSCSI层加入错误校验和恢复(Error Checking and Correcting,ECC)机制,提高了协议的可靠性。当接收端接收到的大数据包出现错误时,包头和包内数据块单元的头部出现的错误将被检测定位,然后被纠正;当接收端收到的小数据出现错误时将会采用重传机制来解决。这个机制可以提升存储网络的传输效率,减轻了网络的负担。在网络仿真平台NS-2上对两种协议进行了仿真,对仿真结果进行了分析。仿真结果表明RH-SCSI可以提高传输效率和可靠性,具有较好的错误恢复机制。更多还原

【Abstract】 Storage systems have faced more and more challenges with the development of computer technique and networks, including higher I/O speed, larger storage capacity, security, expansibility and usability. The OBS(Object Based storage System) fits in with the next generation Internet. The OBS makes up of computer node, object-based storage device(OSD), metadata server and network. The storage network is the important factor of affecting the performance of OBS.We present a RH-SCSI(Reliable HyperSCSI) protocol, which is designed based on HyperSCSI. It can establish high-performance storage system, because it was desighed for transmitting SCSI data and it makes use of existing Ethernet infrastructure, existing hardware part. It has shown to have more stronger functions initially than iSCSI. But HyperSCSI is insufficient in reliability.To overcome the shortcoming of it, we present a RH-SCSI(Reliable HyperSCSI) protocol, which adds ECC(Error Checking and Correcting) mechanism to HyperSCSI layer. The strategy of RH-SCSI is that adding ECC mechanism to HyperSCSI layer. While the large size packet data received is error, error data could be checked and corrected. In case of little size data and command packets are error, RH-SCSI source re-transmits the error packets based on acknowle-dgement policy. These mechanism raises the throughput of the storage network, lightens the burden of the network. The performance of RH-SCSI is analyzed, and the simulation results on NS-2 show that the presented protocol is efficient.更多还原