Based on cluster resource utilization, a DRS-enabled cluster can reduce its power consumption by powering on or off ESXi hosts through the vSphere Distributed Power Management (DPM) feature.
Memory and CPU resources demanded by VMs in the cluster are compared with the total resource capacity that's available from the hosts in the cluster. If the cluster is providing excessive resources, one or more hosts are placed in standby mode by DPM and powered off after migrating the VM to other hosts. When the capacity that's provided is deemed not sufficient, DRS powers the host on, bringing them out of standby mode and vMotions the VMs to them.
vSphere DPM can use three protocols to bring a host out of standby mode:
- Intelligent Platform Management Interface (IPMI)
- Hewlett Packard Integrated Lights-Out (iLO)
- Wake-On-LAN (WOL)
vSphere DPM can put a host in standby mode only if at least one protocol is supported. If a host supports multiple protocols, the following order is used: IPMI, iLO, WOL.
Before you can start using DPM, you must configure the IPMI/iLO/WOL configuration for each ESXi host. To do that, perform the following operation for each ESXi hypervisor:
- Switch to the Configure tab of the ESXi hypervisor
- Navigate to System and select Power management
- Click Edit to configure the IPMI/iLO settings for power management:
User name and Password are the credentials for the out-of-band management module. BMC IP address is the IP address of the module. You must also configure the MAC address of the BMC because it will be used for the Wake-On-Lan feature if IPMI / iLO communication fails.
You can invoke power management features of the ESXi server from the vSphere client as shown in the following screenshot:
