added note on os x file limits

docsite/rst/intro_installation.rst

@@ -50,6 +50,12 @@ Currently Ansible can be run from any machine with Python 2.6 or 2.7 installed (
 
 This includes Red Hat, Debian, CentOS, OS X, any of the BSDs, and so on.
 
+.. note::
+
+    As of 2.0 ansible uses a few more file handles to manage it's forks, OS X has a very low setting so if you want to use 15 or more forks
+    you'll need to raise the ulimit, like so `sudo launchctl limit maxfiles 1024 2048`. Or just any time you see a "Too many open files" error.
+
+
 .. _managed_node_requirements:
 
 Managed Node Requirements