Performance analysis of a fibre channel switch supporting node port identifier virtualization: Preliminary results

The server virtualization architecture, encompassing the sharing of data storage subsystems among the virtual servers or operating systems on a single host server using I/O channel sharing capabilities in fibre channel fabrics, was pioneered by IBM through their system z⁹ mainframe and its predecessors. The implementations of I/O channel sharing capabilities were based on the fibre connectivity channel standard. With the advent of sharing small computer system interface devices among host servers in storage area networks using the fibre channel protocol, certain problems arose in sharing the I/O channels between virtual servers on a host. To implement server virtualization with this new environment, IBM invented the N-Port identifier virtualization architecture, which is now part of the fibre channel standards. This paper examines the performance of a fibre channel switch supporting N-port identifier virtualization. In particular, the switch latency for discover fabric services command during the process of granting multiple virtual N-port identifiers to single and multiple hosts, hosting a large number of virtual servers is examined.