if server name is too long change server_names_hash_bucket_size in nginx configuration file at /opt/nginx/conf/nginx.conf
If everything goes right passenger_root /usr/local/rvm/gems/ruby-1.9.3-p448/gems/passenger-4.0.21; passenger_ruby /usr/local/rvm/wrappers/ruby-1.9.3-p448/ruby; else make changes in the nginx.conf file (/opt/nginx/conf/nginx.conf)
Later steps: