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

if formatting the tmp directory is not working then try this:

1. first stop all the entities like namenode, datanode etc. (you will be having some script or command to do that)
2. Format tmp directory
3. Go to /var/cache/hadoop-hdfs/hdfs/dfs/ and delete all the contents in the directory manually
4. Now format your namenode again
5. start all the entities then use jps command to confirm that the datanode has been started
6. Now run whichever application you have

Hope this helps.