I have a WordPress site with cPanel (WHM) with VPS. Today I configured Google PageSpeed Service for my WordPress site. After I submitted my WWW domain, PSS automatically added my naked domain (without www) to Hosted By You. PSS works few hours without any issue. Now it's giving me Fetching content failed due to a DNS error.According to this official DNS failure tutorial I added an origin domain to my WP site. If added orgin.mydomain.com (A record) and pointed it to my site IP (VPS main IP), it doesn't display my site. If I added orgin.mydomain.com to PageSpeed Service displays a blank site.How do I fix this issue? How do I setup origin domain name for my site? 
How do I setup origin domain for Google PageSpeed Service?
wordpress;dns;vps;page speed