When "dfs.namenode.safemode.min.datanodes" is configured to n
So namenode will be in safemode until n DN are registered with the namenode .
But in UI it displays that n+1 datanodes are additionally needed. And "safe mode will be turned off automatically " message is also displayed .
Started the NN
The UI report displays that
"Safe mode is on.The number of live datanodes 0 needs additional 3 live inimum number 2. Safe mode will turned off automatically".