Initiating a High Availability failover

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

• Active Node
  • Runs the Active vCenter Server Appliance instance.
  • Uses a public IP address for the management interface.
  • Uses the vCenter HA network for replication of data to the Passive node.
  • Uses the vCenter HA network to communicate with the Witness node.
• Passive Node
  • Is initially a clone of the Active node.
  • Constantly receives updates from and synchronizes state with the Active node over the vCenter HA network.
  • Automatically takes over the role of the Active node if a failure occurs.
  • Is a lightweight clone of the Active node.
  • Provides a quorum to protect against a split-brain situation.

For troubleshooting and testing, you can manually initiate a High Availability failover and have the Passive node become the Active node. A vCenter high availability (HA) cluster supports two types of failover:

• Automatic failover: The Passive node automatically takes over the active role when an Active node fails.
• Manual failover: A user manually forces the Passive node to take over the Active role using the Initiate Failover action. This is done for troubleshooting and testing.

1. In vSphere Client, log on to the Active node vCenter Server Appliance, and then click Configure > Settings > vCenter HA.
2. Click Initiate Failover.
3. Start the failover, click Yes.
   A dialog offers you the option to force a failover without synchronization. In most cases, choose synchronization.