diff --git a/source/reference/mongosync/mongosync-behavior.txt b/source/reference/mongosync/mongosync-behavior.txt index 289552779..cfd9e3c33 100644 --- a/source/reference/mongosync/mongosync-behavior.txt +++ b/source/reference/mongosync/mongosync-behavior.txt @@ -113,6 +113,17 @@ destination cluster. Chunk Distribution '''''''''''''''''' +.. important:: + + Even if the source cluster is balanced, ``mongosync`` doesn't + ensure balance of the destination cluster. Because ``mongosync`` + doesn't support the execution of sharding operations during + migration, you must wait until it is safe to accept writes + to rebalance the destination cluster. See :ref:`sharding-balancing` + for guidance on how to rebalance the cluster and + :ref:`sharded cluster limitations ` + for information on sharded cluster limitations in ``mongosync``. + ``mongosync`` does not preserve chunk distribution from the source to the destination, even with multiple ``mongosync`` instances. It is not possible to reproduce a particular pre-split of chunks from a source