I finally found the correct way to do that. I used Ambari to create a new configuration group that includes the new hosts only, and then I added the extra disks paths to the dfs.datanode.data.dir parameter in the new configuration group only. That will integrate the extra disk on the new nodes only into the HDFS. Older nodes will not be impacted by the change in the parameter.   Reference: https://docs.cloudera.com/HDPDocuments/Ambari-2.7.5.0/managing-and-monitoring-ambari/content/amb_managing_host_configuration_groups.html ... View more