This post explains how to run a custom command or script at system startup on Centos 6.x system.

Simply go to: /etc/rc.d and edit the file called: rc.local

Find the last line in the file and on the new line enter whatever custom command you'd like to run on system boot.

Advantage behind using rc.local is that this is the last boot script which is executed, after all services are initialized, so all commands which typically work when system is up and running, also work when entered here.

Enjoy!