In oVirt-4.0 we introduced integration with metrics collectors, In [1] you will find a guide for utilizing your environment to retrieve visualized reports about hosts and vms statistics.
I encourage to try that out and send us requests for additional valuable metrics that you think vdsm should publish.
This area is still work in progress and we plan to support more technologies and different architectures for metrics collections as describes in the post. This will follow by additional links in the post ([1]) that describe how to do so.. stay tuned.