DPM and its impact

VMware vSphere Distributed Power Management (also known as vSphere DPM) continuously monitors resource requirements and power consumption across a VMware vSphere DRS cluster. When your vSphere HA cluster needs fewer resources, it consolidates workloads and powers off unused ESXi hosts so that it can reduce power consumption. However, virtual machines are not affected because DRS moves the running VMs around without downtime as needed, while hosts power off and on. ESXi hosts are kept powered off during periods of low resource use. But when there is a need of more resources then DPM powers on those ESXi hosts for the virtual machines to use. vSphere DPM uses three techniques to bring the host out of standby mode and those techniques are as follows:

• Intelligent Platform Management Interface (IPMI)

• Hewlett-Packard Integrated Lights-Out (iLO)

• Wake on LAN (WOL)

If a host supports all of them then the order of the technique chosen for use by DPM is as ordered above. However, for...