A customer has many Linux guests hosted by z/VM. The customer wants to use their FCP CHPIDs more efficiently. Which mechanism will allow this?

Luis F.Jun 1, 2026

D is the right answer here. NPIV (N_Port ID Virtualization) works by virtualizing on the CHPID N_Port side going out to the switch F_Port, which lets z/VM assign each Linux guest its own virtual N_Port ID over a single physical FCP CHPID, so you get way better utilization without needing a dedicated CHPID per guest.

Fatima Z.Jun 26, 2026

D all day, and here is the hook that locks it in forever. Picture your CHPID as a hotel front desk, the N_Port is the single door into that hotel, and the switch F_Port is the street outside. NPIV lets that one door hand out dozens of virtual room keys, one per Linux guest, so every guest looks like its own unique traveler to the SAN fabric even though they all squeeze through the same physical CHPID. The mnemonic is DOOR, meaning D is correct, One physical port, Opens into the switch F_Port, Results in many virtual N_Port IDs. The supporting detail that seals it is this: z/VM acts as the NPIV manager and assigns each guest a unique WWPN, which means the storage side sees individual hosts and you get cleaner zoning, better LUN masking, and no wasted CHPID overhead from dedicating one per guest.

Haruki E.Jun 11, 2026

C tempts but NPIV is N_Port-side, not IFL-to-CHPID layer, so D.

Ola B.Jun 20, 2026

Spin up a z/VM lab and watch the IFL hand off directly to the CHPID N_Port, that NPIV link is where the multiplexing actually happens.