Will VMs from site A fail to site B if the secondary level of failures to tolerate is reached? So if Site A cluster has SFTT=1, and 1 host goes down, will the VMs which have that SFTT be brought up on site B.
Or does failover of VMs only occur when the site in it's entirety is down?
SFTT doesn't affect whether VMs fail over or not, that is controlled by vSphere HA. You can control the failover behavior using DRS Affinity Rules. Take a look at this and let us know if you have any more questions: