Some Hosts Are Overloaded with FT Virtual Machines

You might encounter performance problems if your cluster's hosts have an imbalanced distribution of FT VMs.

Problem

Some hosts in the cluster might become overloaded with FT VMs, while other hosts might have unused resources.

Cause

vSphere DRS does not load balance FT VMs (unless they are using legacy FT). This limitation might result in a cluster where hosts are unevenly distributed with FT VMs.

Solution

Manually rebalance the FT VMs across the cluster by using vSphere vMotion. Generally, the fewer FT VMs that are on a host, the better they perform, due to reduced contention for FT network bandwidth and CPU resources.