If you are serious about passing RHCSA & RHCE exams, you have to build a lab.
There are very limited explanations in books and almost no article on Internet on this topic (one such article about building a lab for RHCSA/RHCE exams) and it’s not so easy.
This task can be split into several steps:
(if you go the Virtual Box way, my explanations stop here)
- Install a KVM host,
- Configure network settings,
- Set up a repository,
- Configure a DNS service,
- Create a VM guest.
Additional information is available about the virsh command and the KVM configuration in CentOS 6.4.
Furthermore, Dell provides basic installation instructions and more advanced instructions.
Finally, the CentOS wiki offers a tutorial on KVM virtualization.