The Implementation And Performance Of A Practical ISCSI Server Based On Open Source Software

With the increasing data storage needs, traditional storage architecture manifests many problems. Storage networking becomes an important way to handle the challenge. iSCSI is a novel storage networking technology which transports SCSI protocol over TCP/IP network, combining the SCSI and IP/Ethernet technologies, which are standard and mature in storage and network fields respectively. In contrast with traditional Fibre Channel SAN (Storage Area Network) technology, iSCSI enables low-cost SAN to be deployed on ubiquitous IP network, thus becoming a key factor for rapid popularization of networked storage.iSCSI server is a core component for iSCSI application. There were several open source implementations, but they lack features desired in practice. This thesis presents design and implementation of a practical iSCSI server, which borrows from one of the open source reference implementations and has the following main features:1) supporting many target/LU service; 2) supporting common kinds of storage space; 3) a flexible software architecture. By supporting many targets, this server can provide independent or share storage service for many host users, which satisfies with requirements of centralized storage. By supporting common kinds of storage space, SCSI/IDE disk, disk partition, logical volume, and regular file can be configured as a logical unit of SCSI target device and then be exported to host user by iSCSI, thus allying iSCSI with virtual storage technologies based on device. Flexible software architecture is not only exhibited in SCSI/iSCSI two-layer structure, but also in an I/O interface framework which helps extendsion and selecting of other I/O interfaces.We do performance test and find out:1) Choosing write back policy obviously brings better write performance; 2) The iSCSI server runs well when interoperating with the main iSCSI initiators; 3) When many client nodes access, the iSCSI server has better scalability.Moreover, We also introduce its application deployment in Blueware SonD system. The application system has been running for a long term, and accomplished our aims.