Can't start Mongo DB on RHEL

I am working RHEL instance on AWS. I followed the process as on this website http://ift.tt/1fFz29o

The steps I followed.

$sudo yum install -y mongodb-org  
$semanage port -a -t mongod_port_t -p tcp 27017

When I try to start mongo with command

$sudo service mongod start

I get the error message

Starting mongod (via systemctl):  Job for mongod.service failed. See 'systemctl status mongod.service' and 'journalctl -xn' for details.

When I run

$systemctl status mongod.service

I see the following error statement

Failed to start SYSV: Mongo is a scalable, document-oriented database.