To step through this recipe, you need a running ESXi Server with SSH enabled, a couple of running CPU-hungry VMs, an SSH client (Putty), a vCenter Server, and vSphere Web Client. No other prerequisites are required.
The following table elaborates on Esxtop CPU Performance Metrics:
Esxtop Metric | Description | Implication |
%RDY | The percentage of time a vCPU in a run queue is waiting for the CPU scheduler to let it run on a physical CPU. | A high %RDY time (use 20 percent as the starting point) may indicate the VM is under resource contention. Monitor this; if the application speed is OK, a higher threshold may be tolerated. |
%USED | The percentage of possible CPU processing cycles that were actually used for work during this time interval. | The %USED value alone does not necessarily indicate that the CPUs are overcommitted. However, high %RDY values plus high %USED values are a sure indicator that your CPU resources are overcommitted. |