Data node is not starting for hadoop

Check for the folder permission and folder ownership, for HDFSand Hadoop folder,

So change the ownership of the hadoop or hdfs folder you can issue the following command at the shell

chown -R username foldername

Here -R says recursive, so the foldername and the folder under it will be affected and the folder name will be either your Hadoop folder or HDFSfolder if it is created successfully, the you can look into changing the permission of the folder which you can do by issuing the following command at shell

chmod -R 755 foldername

And also you can check if data folder is created sucessfully in hdfs path that you have specified.


Note :




Data node problems mostly arises due to the incorrect permission or incorrect path in the configuration.

Name node problems mostly arises due to the incorrect domain/IP/host name configuration.


So if data node is not starting looking into permission related options and if name node is not running look into host configuration settings.