How to confirm that chunk transfer is completed on a DB
To ensure there are no migrations in progress while taking your backup, you should stop the balancer via sh.stopBalancer(). Any in-progress migrations will be completed before the balancer is disabled.

If you want to ensure the balancer is stopped before taking your backup, you can run the following in the mongo shell, which should return true:

 !sh.getBalancerState() &amp;&amp; !sh.isBalancerRunning()


After taking your backup, you need to remember to start the balancer again.