Run the Disk Balancer plan

For a DataNode, the HDFS Disk Balancer moves data according to the details specified in the JSON document generated as the Disk Balancer plan.

You must have generated the data movement plan for the DataNode.
Run the hdfs diskbalancer -execute command by specifying the path to the JSON plan document.
hdfs diskbalancer -execute /system/diskbalancer/<Creation_Timestamp>/nodename.plan.json

The command reads the DataNode's address from the JSON file and executes the plan.