A vSphere administrator is configuring a fully automated DRS cluster and determines that
DRS is not balancing virtual machine workloads.
What condition could cause this behavior?
A.
vMotion is not properly configured on the hosts in the cluster.
B.
HA is not properly configured on the hosts in the cluster.
C.
The DRS threshold is configured on the most aggressive setting.
D.
Some of the virtual machines have been disabled from DRS.
Should be D. From the vCenter 5.5 Troubleshooting guide, near bottom of page 45
The following are possible reasons why the cluster has a load imbalance:
– The migration threshold is too high.
– higher threshold makes the cluster a more likely candidate for load imbalance.
– VM/VM or VM/Host DRS rules prevent virtual machines from being moved.
– DRS is disabled for one or more virtual machines.
– A device is mounted to one or more virtual machines preventing DRS from moving the virtual machine in order to balance the load.
You forgot even write the last 2 reasons:
– It would be more detrimental for the virtual machine’s performance to move it than for it to run where it is currently located. This may occur when loads are unstable or the migration cost is high compared to the benefit gained from moving the virtual machine.
-vMotion is not enabled or set up for the hosts in the cluster.
Then also the A may be right.