When running CloudForms Cloud Engine 1.0.1 using libvirt-0.9.10-21.el6_3.4, the KVM kernel modules were not automatically loaded by the libvirtd daemon. If the KVM modules were not loaded, attempts to build images to a RHEV or vSphere provider were failing. To workaround this issue, administrators must manually load the appropriate kernel modules. The following command will successfully load the appropriate KVM kernel modules.
# sh /etc/sysconfig/modules/kvm.modules
A future update of the RHEL libvirt package will resolve this issue (BZ#836498). Additionally, CloudForms 1.1 will also resolve this issue during Cloud Engine initial configuration.