User`s guide

134 XgOS User’s Guide • September 2014
vHBA Topology
The following figure displays a typical vHBA topology.
An IB connection exists between the Oracle Fabric Interconnect and host servers
supporting the OVN vHBA host software stack. Up to 24 IB ports are supported. A
2-port FC I/O card connects to a storage area network (SAN) FC switch fabric. All
the host server vHBAs multiplex through the FC ports on the I/O card. A storage
array is attached to the switch fabric. Initiators are host servers that request I/O
processing and actively seek out and interact with target devices on the SAN.
Targets are passive storage devices (arrays, JBODs, RAIDs, and so on) that respond
to requests sent by initiators. The Oracle Fabric Interconnect itself is an I/O initiator
that provides a conduit for host-server initiators to send commands to the fabric.
Note – Some target devices function also as data replicators. In this case, these
targets function also as I/O initiators replicating data (sync) to other locations.
The vHBA host software defines how the FC protocol will be transported (in/out)
over IB. Without this software and the details of the transport, the vHBA will not
function and the payload cannot be sent over IB.
Both initiators and targets have a World Wide Node Name (WWNN) and a World
Wide Port Name (WWPN). A 2-port FC card itself has one WWNN, and each port
has its own WWPN. These IDs register with one another to establish
communication.