The Design Of Access Interface Of Eistributed Storage System

Distributed, high performance application needs the communicating protocol with high bandwith and low latency. The network physical bandwith has been increased rapidly, but traditional network architecture or communicating protocol has not achieved the performance that hardware can support at the application level.VIA is an industry standard in cluster communication. This paper introduce the VIA prococol into storage area and implement one kind of kernel-level VIA prococol. It is developed from the user-level VIA. It eliminates the system-processing overhead of the traditional model by providng each consumer process with a protected,directly accessible interface to the nework hardware – a Virtual Interface. But the VIA requires that the receiver should prepost a descrptor to the receive queue before the sender requests data transfer. To overcome this preposting constraint ,we developed a synchronization mechanism between sender and recerver to guarantee that at least one descriptor is available.In this paper, we describe a design and inplementation of a network block device over VIA for Linux based cluster of PCs. The VIA-NBD is a software layer which offer the abstraction of astorage media across the network.,where a remote server provides the real physical storage.VIA-NBD clients can access the server's disk device as if it were a local one through a virtual device created at the client side.iSCSI intergrates the existing storage protocols with the TCP/IP protocol directly. Then the storage and network can be merged seamlessly. It simplifies the implementation of the storage network and decrease the total cost . Inorder to make the distributed storage system can be accessed by the users in Wide Area Network, we have implemented a remoted access interface of storage system through creating the virtual disk device.