Unable to execute HDFS commands on the terminal

Question

 I have opened terminal and was trying to execute HDFS commands. I am getting the attached error.

Answer 1

Maybe because you have not started hadoop service.

Open terminal and run:

$ sudo jps
$ sudo service hadoop-master restart
$ sudo jps

After this check whether these 4 daemons are up and running or not: Namenode,datanode,Resource manager, Node manager. If yes then try the command hdfs dfs -ls / again.