The NAS can satisfy the requirement of more big capacity,more faster access speed and more easier accessfor the storage system. The conventional NAS usually lacks the cooperation mechanism and can not utilize the re-source of other NAS to get high performance. This paper presents a high performance cooperation write cache mecha-nismfor NAS-ACAWM. ACAWM introducs the automatic cooperation mechanism and asynchronous write mecha-nism into NAS. Automatic combination methanism can make NAS to cooperate each other without artificial configura-tion and asynchronous write mechanism improves the performancc of the file write. The design of ACAWM fully con-siders over the usability of NAS and has no special requirement of the client. At last,this paper uses experiment toprove that ACAWM can greatly improve the performance of NAS.
The MVC designed pattern was developed in Smalltalk-80 and was wildly used in the task of software design. This paper introduces MVC to Web application design, and describes a design pattern based MVC in detail. This design pattern not only detaches the transaction and expression form, but only can improve the maintainability, expandability and performance by using the module library, template library, message object and queue cache. In conclusion, this paper presents a novel Web application design pattern based on MVC.
The access frequency of different files in file system is dissimilar. If file system can optimize the block lay-out of these hot files which are frequently accessed,the performance of file system will be improved. This paper pre-sents a high performance block layout mechanism: Active Block Layout (ABL). ABL can record the access frequencyof every file in file system and actively optimize the block layout of these hot files by block duplicating. The duplicatedblocks can be placed in the special zone of track,which is called "Cooling Zone". ABL can automatically determine theplacing position and the copy count of the blocks which need to be duplicated. In order to reduce the overhead of blockduplication,this paper also presents a mechanism which uses the potential disk bandwidth to realize the block duplica-tion,and does not obviously degrade the performance of file system.
