You can use the Set Up vCenter HA wizard in the vSphere Client to configure the Passive and Witness nodes. The Set Up vCenter HA wizard automatically creates the Passive and Witness nodes as part of vCenter HA configuration. With the manual option, you are responsible for manually cloning the Active node to create the Passive and Witness nodes.

Automatic Configuration with the vSphere Client

You must meet the following requirements to perform automatic configuration.
  • The vCenter Server that will become the Active node is managing its own ESXi host and its own virtual machine. This configuration is sometimes called a self-managed vCenter Server.
If you meet the requirements the automatic workflow is as follows.
  1. The user deploys the first vCenter Server, which will become the Active node.
  2. The user adds a second network (port group) for vCenter HA traffic on each ESXi host.
  3. The user starts the vCenter HA configuration and supplies the IP addresses, the target ESXi host or cluster, and the datastore for each clone.
  4. The system clones the Active node and creates a Passive node with precisely the same settings, including the same host name.
  5. The system clones the Active node again and creates a more light-weight Witness node.
  6. The system sets up the vCenter HA network on which the three nodes communicate, for example, by exchanging heartbeats and other information.

Manual Configuration with the vSphere Client

If you want more control over your deployment, you can perform a manual configuration. With this option, you are responsible for cloning the Active node yourself as part of vCenter HA setup. If you select this option and remove the vCenter HA configuration later, you are responsible for deleting the nodes that you created.

For the manual option, the workflow is as follows.
  1. The user deploys the first vCenter Server, which will become the Active node.
  2. The user adds a second network (port group) for vCenter HA traffic on each ESXi host.
  3. The user must add a second network adapter (NIC) to the Active node if the credentials of the Active management vCenter Server are unknown.
  4. The user logs in to the vCenter Server (Active node) with the vSphere Client.
  5. The user starts the vCenter HA configuration, selects the checkbox to manually configure and supplies IP address and subnet information for the Passive and Witness nodes. Optionally, the user can override the failover management IP addresses.
  6. The user logs in to the management vCenter Server and creates two clones of the vCenter Server (Active node).
  7. The system sets up the vCenter HA network on which the three nodes exchange heartbeats and replication information.
  8. The vCenter Server is protected by vCenter HA.

See Configure vCenter HA With the vSphere Client for details.