You are adding four new nodes to an existing AHV cluster. The Expand Cluster pre-checks in Prism Element fail and report that the new nodes are not compatible with the existing cluster. What is the most likely cause?

Nutanix supports mixed node generations and even mixed models within a cluster, but every node must use the same CPU vendor. AHV live migration copies a running VM's state between hosts, and that only works when the source and destination expose a compatible x86 instruction set; Intel and AMD processors cannot be mixed for that reason, so the Expand Cluster pre-checks reject the new nodes. When generations differ within one vendor, AHV masks the CPU features presented to VMs down to the oldest generation in the cluster, which is why mixing generations is allowed. Free space in the storage pool is irrelevant to expansion, because the new nodes bring their own disks and add capacity rather than consuming it. LCM inventory describes the firmware and software versions installed on nodes so LCM can plan updates; it is not a compatibility gate for adding nodes, and a missing inventory entry would not stop an expansion. Current AOS releases support mixed-generation hardware, so blaming the AOS version for a generation mismatch is a misreading of the support rules. Exam caveat: mixed generations are fine, mixed CPU vendors are not, and expansion also reimages new nodes to the cluster's AOS and hypervisor versions when needed. Operational check: before ordering nodes, confirm the CPU vendor and model of existing hosts in Prism Hardware and compare them with the new nodes' specifications.