You are preparing for a scheduled maintenance window to upgrade AOS on a four-node Nutanix cluster hosting critical production VMs on AHV. The window is tight, and downtime is strictly prohibited. You initiate the upgrade via Prism Element. How does the upgrade process handle the running VMs to meet the zero-downtime requirement?
Select an answer to reveal the explanation.
Short Explanation
Think of a rolling upgrade like changing tires on a moving car—you do one at a time so the ride never stops. Prism handles the heavy lifting by moving your VMs off a node, updating it, and then moving the next batch. You don't need to manually migrate anything or shut down workloads; the system orchestrates the shuffle to keep the cluster up and running throughout the window.
Full Explanation
Nutanix AOS uses a rolling upgrade pattern to preserve availability during maintenance. Prism selects one node at a time, live-migrates its VMs to remaining nodes, updates the CVM and hypervisor, reboots the node, and validates it before continuing. Because the cluster always keeps enough nodes online, storage and compute services remain available throughout the window. A single coordinated reboot of every node would interrupt distributed storage services and remove the redundancy needed to serve I/O, so it cannot satisfy a no-downtime requirement. Manually moving VMs to another cluster before upgrading is unnecessary and increases risk, since intra-cluster live migration is built into the upgrade workflow. Powering off critical VMs also defeats the maintenance objective and is not required when the cluster has capacity to absorb the workload. The workflow also respects cluster quorum and data locality by ensuring that the remaining nodes can continue to serve affected disks before the node is taken out of service. Exam caveat: Do not confuse rolling upgrades with emergency recovery procedures that may require isolated or offline servicing. Operational check: Confirm spare CPU, memory, and storage headroom can absorb the VMs from the node being upgraded without creating hotspots.