KB51: CPU READY TIME OVER 5 PERCENT

With this Alert, Troubleshooter reports that VM and Host performances begin to degrade because CPU Ready Time is becoming too high.

VMware CPU over-subscription means a VM is trying to get access to a physical CPU, but it can’t. This is measured by VMware as “CPU Ready Time”, as a percentage of time. Ideally, ready time should be at zero. On the field, VMware recommends less than 5% ready time for all VMs, while a CPU Ready value of 10% or greater on a vCPU, shows shrinking performance for server workloads.

Troubleshooting:

Typical solutions are to remove unused vCPUs, remove limits, or add more hosts.

Posted in: VMware vSphere