@Husnain Bustam It is safe to run the balancer while other jobs are running if you have default value of dfs.datanode.balance.bandwidthPerSec=1048576 Bytes per second. It is recommended that run the balancer periodically ( may be once per week ) when there is less load on your cluster ( preferably on Weekends ). It is also safe to kill running balancer anytime if it is causing any impact on running jobs etc. Below are some helpful links: https://community.hortonworks.com/articles/43849/hdfs-balancer-2-configurations-cli-options.html https://community.hortonworks.com/articles/26518/hadoop-cluster-maintenance.html https://community.hortonworks.com/articles/43615/hdfs-balancer-1-100x-performance-improvement.html ... View more