Chapter 5. Red Hat OpenShift installation planning and considerations 83
To force the VM placement (in general based on different rack or data center), you can create 
dual Host Groups, as shown in Figure 5-5.
Figure 5-5   PowerVC dualHost Groups (Availability Zones)
Colocation rules
Colocation rules, also known as server groups in OpenStack’s terminology, are used to 
specify that selected virtual machines must always be kept on the same host (affinity) or can 
never be placed on the same host (anti-affinity).
During deployment, migration, and remote restart, PowerVC ensures that these colocation 
rules are followed.