You need to set the HA mode and enable storage failover functionality to get the benefits of an HA pair.
Commands for setting the HA mode
The HA license is no longer required in Data ONTAP 8.2, yet there are specific Data ONTAP commands for setting the HA mode. The system must be physically configured for HA before HA mode is selected. A reboot is required to implement the mode change.
Configuring a node for non-HA (stand-alone) use
By default, storage controllers are configured for use in HA mode. To use a controller as a single node cluster, you must disable the controller failover functionality and change the node to non-HA mode.