Design And Implementation Of The Tape-Library Virtualization Storage System

With the rapidly developing of information technology and network technology, and the enhancing of people's awareness for data security, TB or even PB-level data need to be backup and archived. Because of the tape-library device with large capacity and shared logical storage pool, hierarchical storage system and network storage system become effective ways for massive data storage and backup. With the storage virtualization technology for tape-library, high-performance SCSI disk (RAID) and SCSI tape-library are abstracted to a virtual-disk storage device, as a shared logic storage unit in the IP-SAN. Using iSCSI protocol, clients store and backup their data conveniently to the tape-library virtualization storage system which can be accessed as a local SCSI disk.The SCSI target emulator for the tape-library storage system is designed and implemented. After installed into Linux kernel, the system is mapped as a device of general SCSI disk. Data for backup and storage is transferred via iSCSI to the tape-library virtualization storage system as the SCSI target, and analyzed by the SCSI target middle level with the form of SCSI commands. Finally the I/O requests are executed by the Linux kernel SCSI sub-system. The data for backup is first stored in high-performance SCSI disk (RAID), and then transferred to the tape-library for archiving in suitable conditions. This idea of backup in disk and archiving in tape ensures high efficient of the SCSI disks (RAID), and is also the specific performance using the information life cycle theory.The result of system test shows that, the tape-library virtualization storage system can complete all the read and write operations as a general SCSI disk, and has obvious advantages than general tape-library in the response time of data backup requests.