[ovirt-users] Sizing hardware for hyperconverged with Gluster?

I have a reasonable feel for how to size hardware for an oVirt cluster with external storage (our current setups all use iSCSI to talk to a SAN). I'm looking at a hyperconverged oVirt+Gluster setup; are there guides for figuring out the additional Gluster resource requirements? I assume I need to allow for additional CPU and RAM, I just don't know how to size it (based on I/O I guess?). -- Chris Adams <cma@cmadams.net>