Hosts are not powered off when the total cluster load is low.

Problem

Hosts are not powered off when the total cluster load is low because extra capacity is needed for HA failover reservations.

Cause

Hosts might not be powered off for the following reasons:

  • The MinPoweredOn{Cpu|Memory}Capacity advanced options settings need to be met.
  • Virtual machines cannot be consolidated onto fewer hosts due to their resource reservations, VM/Host DRS rules, VM/VM DRS rules, not being DRS-activated, or not being compatible with the hosts having available capacity.
  • Loads are unstable.
  • DRS migration threshold is at the highest setting and only allows mandatory moves.
  • vMotion is unable to run because it is not configured.
  • DPM is deactivated on the hosts that might be powered off.
  • Hosts are not compatible for virtual machines to be moved to another host.
  • Host does not have Wake On LAN, IPMI, or iLO technology. Either one is required for DPM to enter a host in standby.

Solution

Address the issue that prevents hosts from being powered off when the total cluster load is low.