High availability (HA) deployment mode includes active and standby nodes to ensure that services are not interrupted.
An HA deployment runs on 3 ESXi hosts and includes at least 10 virtual machines. These include two load balancers, three database nodes, two controllers, the OpenStack Management Server, the OpenStack template, and at least one compute driver. In VDS networking mode, an additional two nodes are required for DHCP.
An additional compute driver is created for each compute cluster that you add to your deployment.