NPIV limitations when virtualizing FC ports are as follows:
NPIV ports must not be used for booting on bare metal systems.
NPIV ports are best used in SANs with a relatively small number of ports, either virtual or physical. Some of the targets in a SAN might not have enough resources to process the large number of ports that NPIV can create. This limitation exists because processing state change notifications (SCN) on the SAN takes significant time if a large number of ports are on the SAN. You can work around this limitation on a large SAN by using zoning, which can limit the number of visible ports.
Oracle Solaris I/O multipathing can be used with NPIV. Although for real path redundancy you must ensure that different paths are physically redundant.
NPIV is supported only in a Fabric topology, and not in an FC-AL or point-to-point topology.
NPIV ports cannot be created on FC single root I/O virtualization (SR-IOV) virtual functions.
Not all hardware supports NPIV. Both switches and HBAs (although not targets) must support NPIV in a SAN. By specification, HBAs support up to 255 virtual ports, though this capability is defined by the resources on the switch. Switches might need to be updated with the latest firmware levels for NPIV support.
For more information about booting from vHBA, see Booting From a Virtual LUN in Oracle VM Server for SPARC 3.3 Administration Guide Booting From a Virtual LUN.