When you create or remove LUNs on a storage system, the managed disk (MDisk) view is not automatically updated. To update this view, you must issue a CLI command or use the management GUI.
You must issue the detectmdisk command or use the Discover MDisks function from the management GUI to have the clustered system (system) rescan the Fibre Channel or iSCSI network. The rescan process discovers any new MDisks that were added to the system and rebalances MDisk access across the available storage system ports.