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VMware vCenter High Availability

vCenter HA help us to protect vCenter Server against failures such as hardware or complete host failures, network failures or isolation, storage failures, vCenter Server application or service failures and vCenter operating system failures.

I will not describe what exactly vCenter High Availability (VCHA) is, because you can find many articles about it on the VMware website (link here).

However, I would like to show you that the process of creating VCHA is very easy and fast. Of course, you must remember that this configuration must be removed before each vCenter server upgrade / update. However, on the other hand, it gives us a really great value when securing our management server.

As a side note, I will only mention that in the early versions of this solution, which has been with us since version 6.5, things were different and I saw that this solution did not always work as it should. However, in the current version I am very satisfied with vCenter HA and I recommend using this solution wherever possible.

We start the process of creating vCenter HA by going to the configurator, which can be found after selecting the vCenter server and going to the “Configure” tab and then to “vCenter HA”.

After starting the configuration process, we will have to provide the network that we will use for communication between the active and passive nodes, but also between the witness. I recommend creating a dedicated port group for this occasion.

The next stage will be to choose where the new servers are to be deployed, the recommendation here is simple – it is best to choose a different compute and storage cluster. If selecting another cluster is not possible, remember to create an affinity rule.

After pressing the “Edit” button for each machine, we will start the configuration wizard.

Selecting a compute cluster



At the end we get a summary

The next step will be to complete the same information for Witness VM, with the difference that here we will only indicate the HA network, because this machine does not participate in management traffic and its function is to create a quorum in the event of a failure.

After defining the resources, the next step will be to enter network data for the network, management and VCHA:

Once you have completed the mentioned step, you can complete the configuration process and wait for the vCenter HA cluster to be created. When creating new servers and configuring them, you will be able to see the entire configuration, but the server status will still be Unavailable.

After the vCenter cloning tasks are completed, you may see the following error:


PostgreSQL replication is not in progress. Verify if PostgreSQL server is running on the Passive node and that the Passive node is reachable on the vCenter HA network.

Automatic failover is not allowed. Manual failover is allowed.

This is nothing to worry about as soon as you create the VCHA, wait a few minutes and let everything run and replicate the differences. In my case, I happened to be in a backup window, so I had to wait over 5 minutes. However, after this time the error disappeared.

Thanks, PD



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