There are some excellent instructions for hand editing the network scripts.
RHEL / CentOS / Scientific Linux
RHEL / CentOS / Scientific Linux Based Posts
Transparent Huge Pages (THP) was introduced in RHEL 6. However, it wasn't turned on by default until RHEL 7.
RHEL/CentOS/Scientific Linux 7 has stopped using iptables and start now using firewalld which provides a dynamically managed firewall.
To convert a ppk file to something ssh can use.
Based on an Article at http://dougsland.livejournal.com/121262.html
yum: prevent a package to be updated in your system
1) Enable the yum-plugin-versionlock