6.5.1

7 Patching a vCenter High Availability Environment on page 78
You can patch a vCenter Server Appliance which is in a vCenter High Availability cluster by using the
<codeph>software-packages</codeph> utility available in the vCenter Server Appliance shell. For
more information, see vSphere Upgrade.
Plan the vCenter HA Deployment
Before you can congure vCenter HA, you have to consider several factors. A vCenter Server Appliance
deployment can use an internal or external Platform Services Controller. A browneld deployment with
components that use dierent versions of vSphere requires dierent considerations than a greeneld
deployment that includes only vSphere 6.5 components. Resource and software requirements and the
networking setup must also be considered carefully.
vCenter Architecture Overview
A vCenter HA cluster consists of three vCenter Server Appliance instances. The rst instance, initially used
as the Active node, is cloned twice to a Passive node and to a Witness node. Together, the three nodes
provide an active-passive failover solution.
Deploying each of the nodes on a dierent ESXi instance protects against hardware failure. Adding the three
ESXi hosts to a DRS cluster can further protect your environment.
When vCenter HA conguration is complete, only the Active node has an active management interface
(public IP). The three nodes communicate over a private network called vCenter HA network that is set up
as part of conguration. The Active node and the Passive node are continuously replicating data.
Figure 4‑1. vCenter Three-Node Cluster
vCenter (Active)
HA Interface
vCenter (Passive)
Witness
vCenter HA
Network
HA Interface
Mgmt Interface
All three nodes are necessary for the functioning of this feature. Compare the node responsibilities.
vSphere Availability
58 VMware, Inc.