Datanode process not running in Hadoop

Question

I set up and configured a multi-node Hadoop cluster using this tutorial.

When I type in the start-all.sh command, it shows all the processes initializing properly as

Answer 1

Delete the files under $hadoop_User/dfsdata and $hadoop_User/tmpdata then run:

hdfs namenode -format

finally run:

start-all.sh

Then your problem gets solved.