added memory comment

lukeforehand · lukeforehand · commit 0f24cee5b2bc · 2015-06-13T12:46:10.000-05:00
diff --git a/README.md b/README.md
@@ -16,6 +16,7 @@ docker build --rm -t sequenceiq/spark:1.4.0 .
 
 ## Running the image
 
+* if using boot2docker make sure your VM has more than 2GB memory
 * in your /etc/hosts file add $(boot2docker ip) as host 'sandbox' to make it easier to access your sandbox UI
 * open UI ports when starting image
 ```
