To monitor the CPU usage of all virtual machines in a specific host cluster, what is the first action an administrator should take?

To monitor the CPU usage of all virtual machines within a specific host cluster, the most effective first action is to click on the cluster and add an alarm. Adding an alarm at the cluster level allows the administrator to set up monitoring that applies to all virtual machines contained within that cluster simultaneously. This method ensures a comprehensive and efficient way of tracking CPU usage without the need to configure individual alarms for each virtual machine.

Setting the alarm on the cluster aggregates the CPU usage data and allows the administrator to receive notifications or take action based on overall cluster performance rather than focusing on each virtual machine separately. This approach is crucial for maintaining optimal resource allocation and performance in environments where multiple virtual machines share resources within a cluster.

In contrast, adding alarms at the VM or ESXi host level would not provide the same level of holistic monitoring for the entire cluster, limiting the insights the administrator could gather regarding the performance of all hosted virtual machines collectively.