In previous versions assigning the "PowerUserRole" to a user over a data center or cluster allowed the user to create virtual machines. The user was only permitted to view virtual machines which they had created. In Red Hat Enterprise Virtualization 3.1 this behavior has changed to provide increased permission granularity for objects. The "PowerUserRole" now grants full control over the data center or cluster including the ability to view the virtual machines it contains.
The new "VMCreator" role grants permissions similar to those of the old "PowerUserRole". Users with the VMCreator role over a data center or cluster are able to create virtual machines, but are only permitted to view virtual machines which they themselves created.