NPIV is an extension to a standard already defined in the fibre channel protocols that allows one to get past single initiator/single target design limitations. In order for you to take advantage of this, both the HBA (in the host and the storage array) and the switch must support NPIV to generate and publish (allow) an additional world wide port name (WWPN) in a virtual fashion. There is an inevitable collision of ideals going on here, in that virtual server environments want to use virtual storage environments. With the HBA, the switch and the storage array having the ability to create the "virtual" fabric, it will allow for single use connections, similar to VPNs or VLANs or other technologies that want a "dedicated" and secure path from the virtual server to the virtual LUN, with LUN masking and communications intact from point-to-point. This allows for traffic segregation and addresses a host of other potential storage area network issues.
This was first published in May 2007