There is no industry standard for who reports what to the FC Name Server, so OCI makes a best effort attempt to parse that which is reported as HBA model/firmware/driver/vendor.
You may have a specific hba driver + OS permutation that does not report anything usable to the FCNS, or does not report model.
I know HPUX never reports anything useful for HBA information, so OCI cannot report any of this info for HPUX servers.
Vfiler - OCI knows vfiler as an attribute on an internal volume (flexvol), but does not model the vfiler as an object in and of itself.
In your environment, is there a 1:1 relationship between flexvols and vfilers?