MongoDB Documentation, Release 3.0.4 Enable the Balancer Disable Balancing During Backups Disable Balancing on a Collection The sh.disableBalancing() method accepts as its parameter the full namespace of the collection. sh.disableBalancing("students.grades") For example: To disable balancing on a collection, connect to a mongos with the mongo shell and call the sh.disableBalancing() method. When you disable balancing on a collection, MongoDB will not interrupt in progress migrations. You can disable balancing for a specific collection with the sh.disableBalancing() method. You may want to disable the balancer for a specific collection to support maintenance operations or atypical workloads, for example, during data ingestions or data exports. When the backup procedure is complete you can reactivate the balancer process. !sh.getBalancerState() && !sh.isBalancerRunning() Before starting a backup operation, confirm that the balancer is not active. You can use the following command to determine if the balancer is active: If you turn the balancer off while it is in the middle of a balancing round, the shut down is not instantaneous. The balancer completes the chunk move in-progress and then ceases all further balancing rounds. If MongoDB migrates a chunk during a backup (page 184), you can end with an inconsistent snapshot of your sharded cluster . Never run a backup while the balancer is active. To ensure that the balancer is inactive during your backup operation: From a driver that does not have the sh.startBalancer() helper, issue the following from the config database: db.settings.update( { _id: "balancer" }, { $set : { stopped: false } } , { upsert: true } ) From the mongo shell, issue: sh.setBalancerState( true ) Use this procedure if you have disabled the balancer and are ready to re-enable it: 1. Connect to any mongos in the cluster using the mongo shell. 2. Issue one of the following operations to enable the balancer: • Set the balancing window (page 716) so that the balancer is inactive during the backup. Ensure that the backup can complete while you have the balancer disabled. • manually disable the balancer (page 717) for the duration of the backup procedure. Chapter 10. Sharding 718