DRS does not evacuate a host requested to enter maintenance mode or standby mode.

Problem

When you attempt to put a host into maintenance or standby mode, DRS does not evacuate the host as expected.

Cause

vSphere HA is enabled and evacuating this host might violate HA failover capacity.

Solution

There is no solution. If appropriate, disable vSphere HA before you attempt to put the host into maintenance mode or standby mode.