Quick Tip - Resizing vSphere with Tanzu Supervisor Control Plane VMs

During the enablement of vSphere with Tanzu, users can specify the size (Tiny, Small, Medium and Large) which will then dictate the amount of CPU and Memory that is allocated for the Supervisor Control Plane VMs.

After vSphere with Tanzu has been successfully enabled, you will find that only a subset of the settings can be re-configured but the Size is not one of those settings.

There was a question recently asking if you could resize the resources for the Supervisor Control Plane VMs? Although the vSphere UI does not allow you to modify the Control Plane Size value, the vSphere with Tanzu REST API can be used to perform this operation.

In the example above, my vSphere with Tanzu environment is configured using the size Tiny and I wish to change it to the size Small

Using PowerCLI, we can take advantage of the new Set-WMCluster cmdlet to update the -SizeHint property to our desired size.

Set-WMCluster -SizeHint small

This operation will take a couple of minutes and you should now the Supervisor Control Plane VMs getting reconfigured as CPU and Memory is hot-added. If you have the available physical resources, these operation should successfully complete and the PowerCLI cmdlet should return with success as shown in the screenshot below.

If we now navigate to our vSphere with Tanzu cluster under Configure->Namespaces->General, we should see that the Supervisor Control Plane Size has been updated with our desired configuration, which should also be reflected in the CPU/Memory of each of the VMs.

Note: It is important to note that although you can resize the CPU/Memory resources of the Supervisor Control Plane VMs, there are other settings such as the Service CIDR which can not be resized. Depending on your requirements, you may also need a larger Service CIDR for your workloads and that would require disabling vSphere with Tanzu and re-enabling with the desired values. For this reason, you may consider allocating a larger Service CIDR for future growth and when additional compute resources is required, you can simply perform the resize operation.