The way how BIND9 running in a chroot environment is started changed
between CentOS 6 and CentOS 7.

For more information, please read the following Red Hat Knowledgebase
article located at Customer Portal:
https://access.redhat.com/site/node/770133/

The article describes:
- How BIND can be run in a chroot environment on CentOS 7
- What is the difference compared to CentOS 6
- Recommendations when running BIND in a chroot environment