The preference in fog is to make all of these attributes lowercase and make them as similar to the existing models as possible that way the code is more portable across providers. You should be able to make use of the attribute method's `:aliases` option to help map OpenNebula attributes to fog. You can see that I do that [here](https://github.com/fog/fog/blob/master/lib/fog/rackspace/models/compute_v2/server.rb#L112) in the Rackspace provider to map the json document's `OS-DCF:diskConfig` to `:disk_config`.

Let me know if you need any help on this.