A consultant is preparing to add new nodes into an existing cluster.

When adding a new node with a higher AOS version (5.9) into an existing cluster running an older version (5.8), the recommended method is to use Prism Element to expand the cluster and select the re-image option. This process involves re-imaging the new node to the AOS version currently running in the cluster (5.8), ensuring compatibility and stability across the cluster without requiring an overall upgrade to a newer version. This approach maintains the cluster's operational integrity while integrating the new hardware.References: Nutanix Bible, NCS-Core 6.8 official training materials, and Nutanix support documentation on cluster expansion.