[ovirt-users] HA of VMs

I've been poking around for a better way to perform HA. With VM's like IPA or even HA web sites behind an HAProxy; how do I ensure that they are never on the same host? I've seen the options for watchdog and I can see where that may help a little, but not without the initial outage to trigger the alert. There are many ways to do this however I see few that scale. I'm sure I'm missing something and I really appreciate any guidance. Thanks all