vCenter High Availability (vCenter HA) protects vCenter Server Appliance against host and hardware failures. The active-passive architecture of the solution can also help you reduce downtime significantly when you patch vCenter Server Appliance.

After some network configuration, you create a three-node cluster that contains Active, Passive, and Witness nodes. Different configuration paths are available. What you select depends on your existing configuration.


Before you can configure vCenter HA, you have to consider several factors. A vCenter Server Appliance deployment can use an internal or external Platform Services Controller. A brownfield deployment with components that use different versions of vSphere requires different considerations than a greenfield deployment that includes only vSphere 6.5 components. Resource and software requirements and the networking setup must also be considered carefully.


Regardless of the deployment option and inventory hierarchy that you select, you have to set up your network before you can start configuration. To set the foundation for the vCenter HA network, you add a port group to each ESXi host, and add a virtual NIC to the vCenter Server Appliance that later becomes the Active node.


When you use the Basic option, the vCenter HA wizard creates and configures a second network adapter on the vCenter Server Appliance, clones the Active node, and configures the vCenter HA network.


If you configure the vCenter HA cluster with the Advanced option, you have more control over the environment, and you do not have to meet some of the prerequisites for the Basic configuration. However, you are responsible adding a second NIC to the vCenter Server Appliance, cloning the Active node to the Passive and Witness nodes, and configuring the clones.


After you configure your vCenter HA cluster, you can perform management tasks. These tasks include certificate replacement, replacement of SSH keys, and SNMP setup. You can also edit the cluster configuration to disable or enable vCenter HA, enter maintenance mode, and remove the cluster configuration.


In case of problems you can troubleshoot your environment. The task you need to perform depends on the failure symptoms. For additional troubleshooting information, see the VMware Knowledge Base system.


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.