There are multiple ways to verify that the new node was successfully added.
Run this query from a SQL prompt. The new node(s) will be added using the next consecutive node number(s), so the new node(s) will appear at the end of the resulting display.
sql> SELECT * FROM system.nodeinfo ORDER BY nodeid;
You can also use The CLX Command Line Administrative Tool to view your cluster's status by providing the following at a bash prompt.
shell> /opt/clustrix/bin/clx status
You should see that all nodes appear OK on the display. You may also notice that the data distribution amongst your nodes is not yet balanced.