You can configure vSphere HA to designate specific hosts as the failover hosts.
With the Specify Failover Hosts admission control policy, when a host fails, vSphere HA attempts to restart its virtual machines on any of the specified failover hosts. If this is not possible, for example the failover hosts have failed or have insufficient resources, then vSphere HA attempts to restart those virtual machines on other hosts in the cluster.
To ensure that spare capacity is available on a failover host, you are prevented from powering on virtual machines or using vMotion to migrate virtual machines to a failover host. Also, DRS does not use a failover host for load balancing.
If you use the Specify Failover Hosts admission control policy and designate multiple failover hosts, DRS does not attempt to enforce VM-VM affinity rules for virtual machines that are running on failover hosts.
The Current Failover Hosts appear in the vSphere HA section of the cluster's Summary tab. The status icon next to each host can be green, yellow, or red.
Green. The host is connected, not in maintenance mode, and has no vSphere HA errors. No powered-on virtual machines reside on the host.
Yellow. The host is connected, not in maintenance mode, and has no vSphere HA errors. However, powered-on virtual machines reside on the host.
Red. The host is disconnected, in maintenance mode, or has vSphere HA errors.