The Design Of Tree Structure Storage System And Mid-Layer Cache Technology

Redundant arrays of inexpensive disks are widely used in storage servers. But the finite bandwidth of the system bus limits the parallel of the bottom storage channels; Performance of each access technologies used in the storage system also limits the performance of system. So it is necessary to solve the bottleneck of the system bus and lessen the performance distinction of the access technologies.Tree structure storage system uses the tree structure for the data organization and management, and changed the tranditional model of data management. Tree structure can solve the bottleneck of the system bus and reduce the competition probability effectively, because of its multi-channel character and its parallel; The high scalability of the tree structure make the storage system update easily, and also enhance the scalability of the storage system; cache technology of the channel that is used in the tree structure storage system can lessen the performance distinction of the access technologies.Tree structure storage system is consisted of control cell, that use upward channel and downtrend channel to connect to the host or other control cell. The leafage of this storage system is made of disks. There are three main method for the data distribution of the tree structure storage system: striping method(DT0), Mirroring distribution method(DT1), Parity distribution method(DT2).Tree structure have solved the problems of bandwidth matching, polymerization bandwidth and so on. It makes the devices that have different access technology work together and transfer the data parallel. Compared with RAID, tree structure storage system increases the parallel and expansibility of the storage system.