Optimizing host power consumption

vSphere offers two features that allow reducing the power consumption by hosts during off-peak hours. The first one is Distributed Power Management (DPM). It allows reducing a cluster's power consumption by placing certain hosts in standby mode. When the current load and resource reservations allow so, DPM migrates virtual machines off of the host and puts the host in standby mode. When more resources are needed, the host will be taken out of standby mode and used to host VMs.

While DPM places the entire host in the reduced power consumption state, the other feature called Host Power Management (HPM) allows reducing the host power consumption by placing only certain hardware into the low power consumption state. Devices or components in this state are inactive or run at a lower speed.

Getting ready

For DPM to work properly, ESXi hosts should support at least one of the following protocols so that vSphere is able to bring them back up from standby mode:

• Wake...