Relationship of WWPNs and iSCSI names for host objects

A host can be created with worldwide port names (WWPNs) or iSCSI names. The WWPN name space and the iSCSI name space within the system share the same internal system resources.

The iSCSI name in a host object can take up to a maximum equivalent of four WWPNs depending on the number of I/O groups in which the host participates. This affects the maximum number of hosts that you can configure in a system.

Each system I/O group can have up to 512 WWPN entries. Each system I/O group can have up to 256 iSCSI IQNs.

Creating an iSCSI host object with one iSCSI name in one I/O group is equivalent to creating a Fibre Channel host with one WWPN.
Creating an iSCSI host object with two iSCSI names in one I/O group is equivalent to creating a Fibre Channel host object with two WWPNs.

Host (and other system) limits are described here:

http://www-01.ibm.com/support/docview.wss?uid=ssg1S1004368