DOCSP-44876-rolling-index-limitation (#457)

source/reference/limitations.txt

@@ -171,3 +171,17 @@ System Collections
 ------------------
 
 .. include:: /includes/collections/behavior-system-collections.rst
+
+Rolling Index Builds
+--------------------
+
+``mongosync`` does not support :ref:`rolling index builds
+<index-building-replica-sets>` during migration. To avoid building
+indexes in a rolling fashion during migration, use one of the following
+methods to ensure that your destination indexes match your source
+indexes:
+
+- Build the index on the source before migration.
+- Build the index on the source during migration with a non-rolling
+  index build. 
+- Build the index on the destination after migration.