vCenter 6.7 High Availability Configuration – PART 3

Posted By Rajesh Radhakrishnan November 24 2019

In the previous posts, we have discussed VMware vCenter High Availability and Configuration, in this article we will go through the failover scenarios, how to remove vCenter HA configuration, backup and restore operation.

vCenter HA Monitoring

You can monitor the vCenter Server HA status from “vCenter HA option from Configure Tab”, All the three nodes Active, Passive and Witness status should be up and State Healthy.

HA Cluster Maintenance

Once Configure the vCenter HA will be enabled and failover will be performed automatically once the Active vCenter is failed. There is another two-option available to manage the vCenter HA cluster

  • Navigate to vCenter HA area and click on Edit button

Maintenance Mode

When you edit the vCenter HA cluster configuration, you can disable or enable the cluster, place the cluster in maintenance mode, or remove the cluster.

The maintenance mode option is used for some maintenance tasks and vCenter HA automatic failover will be disabled with maintenance mode. Manual failover is allowed in maintenance mode and the replication still works between Active and Passive nodes. This option is can be used to perform an update of the vCenter Server.

  • Navigate to vCenter HA area and click on Edit button
  • Select Maintenance mode and Click Ok

 

 

In few seconds the Enabled mode will change to maintenance and a message will be visible Automatic failover is not allowed. Manual Failover allowed.

You can change the mode from maintenance to Enabled from Edit option as shown below

The mode is changed to enabled and no warning message.

Disable vCenter HA

Disable vCenter HA option will disable both failover and replication but HA configuration remains intact and Active node continues as a standalone vCenter Server Appliance

  • Navigate to vCenter HA area and click on Edit button
  • Select Disable vCenter HA option and Click Ok

 

The mode is changed to Disabled and Initiate Failover option is Grayed Out, also you will see messaged Automatic and Manual failover is disallowed

You can change the mode to Enabled form edit option from vCenter HA Page

Once you change the mode to enabled, wait for some time for replication and vCenter HA is enabled. And meantime you may see below messages over there

After some time Modes will be enabled and State will we be healthy

vCenter HA Failover

Once the vCenter Server Active, Passive and Witness nodes are deployed, the failover of the HA cluster should be performed on a regular basis to make sure that the cluster is protected. When the failover happens, the Passive node becomes the Active node and a vCenter HA cluster supports two types of failover.

Automatic failover

In this scenario, the Passive node attempts to take over the active role in case of an Active node failure.

Manual failover

In this scenario, you can force a Passive node to take over the active role by using the Initiate Failover action.

Manual Failover Testing

  • Log in to the Active node vCenter Server Appliance and navigate to Configure -> vCenter HA
  • Click on Settings select vCenter HA and click Initiate Failover

Select the Force the Failover Box from the Initiate vCenter HA Failover Popup and Click INITIATE FAILOVER

Note:- You can perform failover without selectin force option, in most cases performing synchronization first is best.

 

In a few seconds failover will start, and you will lose the access to vCenter and if you try to access and you will get below screen says Failover in Progress

After some time once the failover completed, you can verify that the Passive node has the role of the Active node in the vSphere Client.

Backup and Restore Operations

Having a backup plan is additional security and you can back up the Active node in the vCenter HA cluster. And you can restore the active node in case of any failure, note that removes the cluster configuration before you restore the Active node.

And it is very important to Verify the interoperability of vCenter HA and the backup and restore solution. One solution is the vCenter Server Appliance file-based restore.

Follow Below Points for Backup and Restore

  • Back up the Active node Only and do not back up the Passive node and Witness node.
  • Before you restore the cluster, power off and delete all vCenter HA nodes.
  • Restore the Active node.
  • The Active node is restored as a standalone vCenter Server Appliance.
  • Reconfigure the vCenter HA.

Remove a vCenter HA Configuration

You can remove a vCenter HA configuration from the vSphere Client and while performing this task you can choose only to remove the HA configuration or remove configuration and delete the Passive and Witness nodes

  • Log in to the Active node vCenter Server Appliance and click Configure.
  • From Settings select vCenter HA and click Remove VCHA and Click OK

You have the option to delete the Passive and Witness nodes by selecting the checkbox, and it will list the passive and witness node names

And finally, the vCenter HA cluster’s configuration is removed from the Active, Passive, and Witness nodes.

Find the below Points to while Removing HA configuration

  • The Active node continues to run as a standalone vCenter Server Appliance.
  • You cannot reuse the Passive and Witness nodes in a new vCenter HA configuration.
  • Passive and Witness nodes should be removed manually if you performed only remove HA configuration.
  • Even if the second virtual NIC was added by the configuration process, the removal process does not remove the virtual NIC.

Shutdown or Reboot Procedure for vCenter HA Nodes

In case of any requirement or maintenance, if you need to shut down or reboot all nodes in the cluster, you must follow the below procedure. After the activity verify that all nodes join the cluster successfully and that the previous Active node resumes that role.

  • You can Shut down the nodes in a manner first Passive Node, Second Active node, and Last Witness node

You can restart the nodes any order, once rebooted make sure all nodes are joined to the cluster

Change the Appliance Environment

The appliance environment is the size of the infrastructure we select for deployment, For vCenter HA, Small, Medium, Large, and X-Large are supported for production environments. If you need more space and want to change the environment, an example from small to the medium you must delete the Passive node virtual machine before you change the configuration. Check below procedure to change the appliance environment

  • Disable HA configuration.
  • Delete the Passive node virtual machine.
  • Change the vCenter Server Appliance configuration for the Active node
  • Reconfigure vCenter HA.

Conclusion

vCenter Server HA feature is released with version 6.5 and it’s available with the version released 6.5 onwards. This is a great feature provide a higher level of protection for the virtual environment with no additional cost for the license. In this article, we have explained about failover scenarios, how to remove vCenter HA configuration, backup and restore operation, etc. In the fully-functioning HTML5 release of vCenter 6.7 Update 1 onwards the setup of vCenter HA and all the configuration and maintenance tasks are incredibly simplified.