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servers since November 2008. In October 2009, IBM also made NPIV available for IBM i and
Linux on Power servers and for IBM i, AIX and Linux on Power blades.
To leverage NPIV, an IBM i LPAR must have a Virtual Fibre Channel (VFC) client adapter
created, which connects to a VFC server adapter in VIOS, similar to the VSCSI model. However,
the VFC client adapter does not allow IBM i to access LUNs or tape drives already assigned to
VIOS in the SAN. Instead, the VFC server adapter in VIOS is mapped to a FC port on the
physical NPIV-capable adapter. This allows the client VFC adapter in IBM i direct access to the
physical port on the FC adapter, with VIOS having a “passthrough” role, unlike with VSCSI. The
tape drive in the FC tape library for IBM i use is not mapped to the WWPNs of the physical ports
on the NPIV adapter and it does not become available in VIOS first. Instead, when the VFC client
adapter in the IBM i LPAR is created, two virtual WWPNs are generated by the PowerVM
Hypervisor. The tape drive in the library is zoned directly to one of the two WWPNs on the VFC
client adapter in IBM i. Two WWPNs are generated per VFC client adapter to facilitate Live
Partition Mobility, although only AIX and Linux LPARs can leverage it at the moment. The
PowerVM Hypervisor on a Power server or blade has the default capability to create 32,000
virtual WWPNs. When VFC client adapters are deleted, WWPNs are not reused. If all of the
default 32,000 WWPNs are used, the client must obtain an enablement code from IBM, which
allows the creation of a new set of 32,000 WWPNs.
Zoning a tape drive in a FC tape library directly to a WWPN on the VFC client adapter in IBM i
has two important advantages:
•
It allows simpler SAN zoning and I/O virtualization configuration on the Power blade. The
tape drive in the library does not have to be made available to VIOS first and then
assigned to IBM i; instead, it is mapped to IBM i in the SAN
•
From the perspective of both the SAN device (the tape drive in the library) and IBM i, an
NPIV connection is identical to a direct FC connection, which is otherwise not possible on
Power blades. NPIV enables IBM i to recognize and use all characteristics of the FC
device, instead of using it as a generic tape drive virtualized by VIOS
The following diagram presents an overview of accessing a FC tape library through NPIV for IBM
i on a Power blade: