@olivierlambert In my understanding, Anti affinity tags only looks for the tags that are attached to the VM. For example: Datacenter 1 Host 1 VM1-1 Host 2 VM1-2 Datacenter 2 Host 3 VM2-1 Host 4 VM2-2 VM1-1 and VM1-2 should be able to migrate to Host 1 and Host 2. VM2-1 and VM2-2 should be able to migrate to Host 3 and Host 4. But VM1-1 and VM1-2 should never be able to migrate to Host 3 and Host 4. VM2-1 and VM2-2 should never be able to migrate to Host 1 and Host 2. With the current (Anti) Affinity tags, it will only look to the tags attached to the VM, so in the example it would be possible for VM1-1 to go to Host 4, if VM2-2 would be at Host 3 together with VM2-1. But if we could tag the hosts, it would not be possible for VM1-1 and VM1-2 to be on Host 3 and Host 4