I/O groups

For ports within an I/O group, you can enable virtualization of Fibre Channel ports that are used for host I/O operations. With N_Port ID virtualization (NPIV), the Fibre Channel port consists of both a physical port and a virtual port. When port virtualization is enabled, ports do not come up until they are ready to handle I/O, which improves host behavior around node unpends. In addition, path failures due to an offline node are masked from hosts.

The target port mode on the I/O group indicates the current state of port virtualization.

Enabled: The I/O group contains virtual ports that are available to use.
Disabled: The I/O group does not contain any virtualized ports.
Transitional: The I/O group contains both physical Fibre Channel and virtual ports that are currently being used. You cannot change the target port mode directly from enabled to disabled states, or vice versa. The target port mode must be in transitional state before it can be changed to either disabled or enabled states. The system can be in the transitional state for an indefinite period while the system configuration is changed; however, system performance can be affected because the number of paths from the system to the host doubled. To avoid increasing the number of paths substantially, use zoning or other means to temporarily remove some of the paths until the state of the target port mode is enabled.

Enabling port virtualization on an existing system

If you are changing the target port mode for an I/O group in an existing system, complete that the following prerequisite steps:

Review your SAN fabric layout and zoning rules because NPIV has stricter requirements. Ensure that equivalent ports are on the same fabric and in the same zone. Click More Information and select Configuring > Configuration details > Zoning details.
Check the path count between your hosts and the system. Make sure that the number of paths is half of the usual supported maximum. For general guidelines on zoning and NPIV, click More Information and select Configuring > Configuration details > Zoning details.
Ensure that Fibre Channel switches permit each physically connected system port the ability to create two additional NPIV ports.

After you have completed these prerequisite steps, you can enable port virtualization on an existing system by completing these steps:

In the management GUI, select Settings > System > I/O Groups.
Right-click the I/O group on which you want to enable NPIV and select Change Target Port Mode.
On the Change Target Port Mode page, change the mode from Disabled to Transitional.
Click Continue. On the I/O Groups page, verify that the target port mode for the selected I/O group displays Transitional.
Right-click the I/O group, and select Change Target Port Mode.
On the Change Target Port Mode page, change the mode from Transitional to Enabled .
Click Continue. On the I/O Groups page, verify that the target port mode for the selected I/O group displays Enabled.

Enabling port virtualization on a new system

Ensure that you have accurately zoned your new system for NPIV configuration. Click More Information and select Configuring > Configuration details > Zoning details for general zoning guidelines and specific information on zoning considerations for NPIV configurations.

In the management GUI, select Settings > System > I/O Groups.
Right-click the I/O group on which you want to enable NPIV and select Change Target Port Mode.
On the Change Target Port Mode page, change the mode from Disabled to Transitional.
Click Continue. On the I/O Groups page, verify that the target port mode for the selected I/O group displays Transitional.
Right-click the I/O group, and select Change Target Port Mode.
On the Change Target Port Mode page, change the mode from Transitional to Enabled .
Click Continue. On the I/O Groups page, verify that the target port mode for the selected I/O group displays Enabled.