Ok so I am using Rackspace CDN and cname to mydomain.com
How do I disable index for mydomain.com?
Do I just create a robots.txt and .htaccess like how we do on the cpanel?
If I upload robots.txt and .htaccess on the root of my CDN, will mydomain.com still get indexed?
Thanks!
Bumpity bump! Would be interested in knowing this as well! 
Amy
did you try submit to google,
or try ping your site to google ping url ?
https://support.google.com/webmaster.../1663419?hl=en
I created a support ticket and my CDN company did it for me. It was CDN77, I dont know if everyone does the same.
CDNs don't run Apache so htaccess is unimportant.
Just drop in robots.txt on your CDN container so that it's accessible through domain.com/robots.txt
If you find any results on Google for your domain just submit a de-index/takedown request, and read the above linked documentation.