DOCS-2706 add arbiter config options

source/tutorial/add-replica-set-arbiter.txt

@@ -18,6 +18,31 @@ server, monitoring host.
    Do not run an arbiter on the same system as a member of the replica
    set.
 
+Considerations
+--------------
+
+An arbiter does not store data, but until the arbiter's :program:`mongod`
+process is added to the replica set, the arbiter will act like any other
+:program:`mongod` process and start up with a set of data files and with a
+full-sized :term:`journal`. To minimize the default creation of data, set
+the following options to ``true`` in the arbiter's :doc:`configuration
+file </reference/configuration-options>`:
+
+- :setting:`nojournal`
+
+  .. warning::
+
+     Never set :setting:`nojournal` to ``true`` on a data-bearing node.
+
+- :setting:`smallfiles`
+
+- :setting:`noprealloc`
+
+These settings are specific to arbiters. Do not set :setting:`nojournal`
+to ``true`` on a data-bearing node. Similarly, do not set
+:setting:`smallFiles` or :setting:`noprealloc` unless specifically
+indicated.
+
 Add an Arbiter
 --------------