可快速响应的虚拟三级存储系统RAT

Virtual tertiary storage system RAT with fast response performance

利用SCST中间驱动层,将磁盘阵列与磁带虚拟为一种有别于虚拟磁带库的新型三级虚拟存储系统,将用户文件分割存放在阵列和磁带库上,在服务用户请求时,首先由阵列快速响应用户请求的前一部分数据,同时磁带库执行机械操作准备剩余数据,以屏蔽磁带库响应等待时间,并利用磁盘阵列数据冗余特性确保数据可靠保存,形成海量、快速、可靠的第三级存储子系统.经对比测试该系统用于备份应用时,其备份恢复操作的初始响应时间显著小于传统磁带库系统.

Tertiary storage system provides massive capacity at low price,but also bad response performance.Virtual tape technologies employ disk drives as tupes to achieve high-speed data access,but less storage reliability and scalibility.Based on the SCSI target mid-level subsystem for Linux,this paper describs an original virtual tertiary storage system.Unlike VTL,it distributes file data onto disk array and tape library.When serving user requests, data blocks on RAID are transferring to users first,at the same time tape library is preparing the other required data.The time-consuming mechanical operations are overlapped by effectual data transport of RAID.It makes good use of RAID and tape library to form a new tertiary storage system to provide high response,massive capacity and high reliability.The experiments show that the initial response time of backup/restore applications is markedly improved.