In this chapter, a brief description of a cluster with HA was demonstrated. We also learned how to build shared storage as a quorum disk. With the help of the quorum disk, a two-node cluster was configured. Of course, the most important part of a cluster is the fencing devices. In our testing environment, we learned how to build them with the help of Cisco switches.

Besides that, we built our DRBD block device for VM migration, which will be shown to you in the next chapter. In the next chapter, we are going to build a VM that is protected under HA. Also, I am going to show you the behavior of our cluster during different levels of failure.