If you want to increase data storage on your Nutanix cluster, but do not want any AHV VMs to run on that node, you can add a Never-Schedulable Node to your cluster. AOS will not run any VMs on a never-schedulable node, whether at the time of deployment of new VMs, during the migration of VMs from one host to another (in the event of a host failure), or during any other VM operations. Therefore, a never-schedulable node configuration ensures that no additional compute resources such as CPUs are consumed from the Nutanix cluster.

With the release of Foundation 4.1 and higher, any G6 or G7 node can now be used as a storage-only node. You can add any number of never-schedulable nodes to your cluster!

To learn more about the requirements and the procedure to add this node, click here. 

Also, check out KB-6819 for further instructions.