Hello Sir/Madam, I am Currently Pursuing Big-data Administrator Course , a part of Masters Course. I am facing an issue while installing hadoop as a single node cluster and here is my problem description with the screen shot, please help me resolve this query so that i can complete my course. Problem: When i run the following command i get the the error while formatting the name node as show in the screenshot: "HelpHDFS_Installation1.jpg". sudo -u hdfs hdfs namenode -format hdfs dfs -ls / also when i am trying to acess the HDFS file system i am facing an error which says " WARN ipc.Client: Failed to connect to server: 10.142.202.50/10.142.202.50:8020: try once and fail. java.net.ConnectException: Connection refused" You can fin the screeshots of the above problem with filename "hdfs.jpg". Thanks, Bhoja.