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 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.
Computerized data has become critical to the survival of an enterprise. Company must have a strategy forrecovering their data should data lose. RAID is a popular mechanism to offer good fault-tolerance. But RAID can notwork well when one more disks fail. In this paper, we present an efficient Network-based high High-Tolerance Distributed Shared Storage mechanism called FTDSS. FTDSS makes use of disk space of node in Network to build alarge public shared storage space. Users can read/write their file from/to the public storage space from node of net-work Physically File is stored in each node in form of data fragment or XOR verify fragment. Because of redundantXOR fragments, file is available even when two more nodes fail. FTDSS realize distant redundant srorage. At last.this paper use experiment to prove that FTDSS can offer high fault-tolerance and advanced performance.
