VTarget: An Improved Software Target Emulator for SANs

With the increasing of storage scale and complexity, the storage management for heterogeneous environments is becoming more and more important. This paper introduces an improved software target emulator integrated with storage virtualization management called VTarget, and some key technologies are explained in detail. The VTarget system can manage various heterogeneous storage resources and provides one virtualization interface for storage management. It is implemented in the storage network layer in the SAN and can support heterogeneous operation systems. The VTarget system also provides an access control mechanism to enhance device security and adapts multi metadata copy technology to improve reliability. We have implemented a prototype of VTarget system and the testing results showed that the storage virtualization management influences the I/O bandwidth less than 3.6% and less than 8% in latency, which only has a very slight effect on storage performance for the mass heterogeneous storage system management.