7.4.4. Adding LUNs
After a virtual FC adapter has been created and assigned to a physical FC port, LUNs can be assigned to the adapter. The LUNs are assigned directly to the two WWPNs of the virtual FC client adapter. If the specification of the second WWPN is forgotten, this is usually not noticed at first, since only one of the two WWPNs is active at a time (exception with LPM). If an LPM operation is started some time later (or a validation is carried out), it fails, because the previously inactive WWPN is activated on the target managed system and a check is then carried out to determine whether the same storage ports are reachable as via the active WWPN. This is not the case if the second WWPN is forgotten in the zoning and LUN masking configuration. This means that not all LUNs can be accessed on the target managed system. So it is absolutely important to specify both WWPNs of a virtual FC client adapter in the zoning and LUN masking configuration.
If new LUNs are added, they are immediately visible in the SAN if configured correctly, but are not automatically recognized and used by the operating system of the client LPAR. In the case of AIX, the config manager cfgmgr must be started on the client LPAR.