Since the solution is scattered across many posts, I'm posting a short summary of what I did. I am running HDP 2.6.5 image on VirtualBox. Increased my virtual hard disk through Virtual Media Manager In the guest OS,  Partitioned the unused space Formatted the new partition as an ext4 file system Mounted the file system Update the /etc/fstab (I couldn't do it, as I did not find that file In Ambari, under DataNode directory config, added the newly mounted file system as a comma separated value Restarted HDFS (my cluster did not have any files, therefore I did not run the below) Thanks to @Shelton for his guidance.   sudo -u hdfs hdfs balancer ​       ... View more