DOCSP-38679 mongoexport consistency consideration

source/mongoexport.txt

@@ -39,6 +39,9 @@ or CSV export of data stored in a MongoDB instance.
 Run ``mongoexport`` from the system command line, not the 
 :binary:`~bin.mongo` shell.
 
+``mongoexport`` is not a tool for backing up deployments. If you want to
+create a backup solution, see :ref:`manual-tutorial-backup-and-restore`. 
+
 .. seealso::
 
    :binary:`~bin.mongoimport` which provides the corresponding
@@ -171,6 +174,16 @@ For more information on the options available, see :ref:`mongoexport-options`.
 Connect to a Sharded Cluster
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+.. note::
+
+   To avoid data inconsistencies, pause the following actions on your
+   sharded cluster when you run ``mongoexport``. 
+
+   - Cross-shard transactions
+   - Data definition language operations (operations that create and modify
+     collections)
+   - Chunk balancinng 
+
 To connect to a sharded cluster to export its data, you can either:
 
 - Specify the hostname of the :binary:`~bin.mongos` instance in the
@@ -227,7 +240,10 @@ preference <replica-set-read-preference>`:
 
   .. code-block:: sh
 
-     mongoexport --host="mongos0.example.com:27017" --readPreference='{mode: "secondary", tagSets: [ { "region": "east" } ]}' --collection=events --db=reporting --out=events.json [additional options]
+     mongoexport --host="mongos0.example.com:27017"
+     --readPreference='{mode: "secondary", tagSets: [ { "region": "east"
+     } ]}' --collection=events --db=reporting --out=events.json
+     [additional options]
 
 .. _mongoexport-options: