| A Storage-Area Network(SAN) is a important technology in storage field that comprises storage servers(initiators),storage devices(targets) and a network. Most SANs use the SCSI protocol over various storage devices. The IP and Ethernet technologies pushes the IP SAN evolution toward a truly scalable, manageable storage system. The iSCSI protocol is an important protocol to accesss storage device in IP SAN. It uses SCSI protocol and TCP/IP protocol that enable a transport for SCSI over TCP/IP and accessing SCSI I/O devices over an IP network. iSCSI defines its own packets that are referred to as iSCSI Protocol Units(PDUs). iSCSI PDUs consist of a header and possible data. iSCSI PDU is sent as the content of one or more TCP packets because iSCSI runs on the top of TCP/IP.Severs and devices in iSCSI system can be designed to run in different OS platforms. Servers work in a dynamic way to extend storage resource. By the analysing iSCSI protocol and iSCSI system, Different server routines are developed to support iSCSI servers and devices under different OS platforms. The device that user request is translated to logic unit by LUN Masking based on host virtualize technology. By this means,storage devices are dynamically extended.The experiments are based on different conditions. We configured the switch and network cards as 100Mbit network and Gigabit network. According to the result of iSCSI performance test, it is concluded that network bandwidth has a impact on performance data. It is also shown that multi-thread system works better than single thread system because multi-thread can use spare resource. Different OSs make different results. iSCSI run faster under Linux than under Windows2000. At last, we implement RAM Cache,double Cache technology to improve the performance of iSCSI. According to experiments data, write time can be reduced over 30%.
|
PDF Full Text Request