VMware VCHA is a new feature from vSphere 6.5, and it's available only with the vCSA deployment. It's based on a multi-nodes architecture with an active-passive configuration plus a Witness node, and it's designed to reduce downtime when vCSA fails. These features support both deployment architecture, so internal or external PSC.
Deployment and configuration are easy. The first vCSA that is deployed will be the Active node; then, when you start to configure VCHA, one of the first processes will be the cloning of this first VM with two new VMs; the Passive node and the Witness node. During this process, not only the two clones are created, but it's created also a DRS rule for separate the nodes on different hosts for a better resiliency.
When VCHA configuration is complete, only the Active node has an active management...