N_Port ID Virtualization or NPIV is a Fibre Channel industry standard technology that allows multiple N_Port IDs to share a single physical N_Port. NPIV provides the capability to take a single physical Fibre Channel HBA port and divide it such that it appears, to both the host and to the SAN, as though there are multiple World Wide Port Names (WWPNs).

NPIV provides direct access to the Fibre Channel adapters from multiple virtual machine (client partitions), simplifying zoning and storage allocation. Resources can be zoned directly to the virtual client, which has its own World Wide Port Name (WWPN).

The use of NPIV with IBM VIO provides the capability to use a single Fibre Channel port and overlay multiple WWPNs so that it appears to the SAN as both the VIO server and client partitions. NPIV enables the AIX VIO server to provision entire dedicated logical ports to client mLPARs rather than individual LUNs. Client partitions with this type of logical port operates as though the partition has its own dedicated FC protocol adapter. To utilize the NPIV functionality, a new type of virtual Fibre Channel (VFC) adapter is defined on both the VIO and Client. A server VFC adapter can only be created on a VIO server partition; a client VFC adapter can only be created on client partitions. WWPNs are allocated to client VFC adapters when they are defined in the profile, based upon an assignment pool generated from the backing physical adapter.

There is always corresponding one-to-one mapping relationship between VFC adapters on client logical partitions and VFC on the VIOS. That is, each VFC that is assigned to a client logical partition must connect to only one VFC adapter on VIOS, and each VFC on VIOS must connect to only one VFC on the client logical partition.

NPIV support is included with PowerVM Express, Standard, and Enterprise Edition and supports AIX V5.3 and AIX V6.1.

More details on NPIV and how to configure IBM VIO environment is available in IBM documentation.