Agent VMs, such as CVMs (Controller VMs) or Witness VMs, have strict affinity and anti-affinity rules to ensure they remain on specific hosts and maintain data consistency and high availability. If an agent VM is powered off and then manually started on another host, it becomes unresponsive because it breaks these rules.

From the Nutanix Enterprise Cloud Administration (ECA) course materials:

''Agent VMs have specific configuration and affinity constraints. Manually starting them on another host violates these constraints, resulting in the agent VM becoming unresponsive to the cluster.''

Further clarification:

''The cluster expects the agent VM to be on a particular host. Moving it manually to another host breaks this expectation and causes the VM to be unable to properly join the cluster services, leading to an unresponsive state.''

Therefore, it is essential to avoid manually starting agent VMs on different hosts, as doing so can disrupt cluster services.