How PowerVC assigns Fibre Channel ports

When creating virtual Fibre Channel adapters for a new virtual server, IBM® Power® Virtualization Center first selects a Virtual I/O Server on the chosen host, and then selects physical Fibre Channel ports within that Virtual I/O Server. By default, every Virtual I/O Server on the chosen host is used, but custom storage connectivity groups can be used to constrain that selection.

Note: PowerVC does not support the following. Remove the Fibre Channel ports from PowerVC use in these cases:

• There is a direct cable connection from the Fibre Channel port to the storage controller.
• The port has a Fibre Channel loopback test plug attached.

To remove ports from use, go to Storages > FC ports and set the Connectivity column value to None.

Port selection is governed by the Fibre Channel port configuration and storage connectivity group settings. First, the Fibre Channel port configuration settings are used to find a set of candidate ports by following these steps:

1. Does the port have a port tag? If so, does that port tag allow connectivity with this storage connectivity group? If it does not allow connectivity, the port is rejected.
2. Does the port allow connectivity? If not, the port is rejected.
3. Is the port's status OK, or if it has an error, is it an error that is not related to NPIV? If not, the port is rejected.

This process is illustrated in the following figure:

After obtaining a set of candidate ports, PowerVC uses the settings in the storage connectivity group to further narrow the selection as follows:

1. Do the ports connect to the required fabrics, as specified in the NPIV Fabric Access Requirement setting? If not the VIOS cannot be used.
2. For each fabric required, are there enough ports to meet the For each VIOS, number of ports to connect per fabric setting? If not, the VIOS cannot be used.
3. The resulting ports are sorted by Fibre Channel adapter and then are further sorted by those that are the least utilized, when considering all active NPIV connections.
4. The first n ports are chosen and mapped to virtual Fibre Channel adapters, where n is the value specified for For each VIOS, number of ports to connect per fabric.

This process is illustrated in the following figure: