Hi all,
I've seen quite a few posts with people using similar scenarios of running gluster and ovirt on the same physical box so I think this may be relevant. After some discussions on the gluster mailing list, I put together a quick post [1] about how you can limit glusters CPU resources so when it comes to self-healing etc. your VMs will have higher priority and not crawl to a halt when glusterfsd takes all the resources.
So far, I haven't been able to apply these cgroup rules without losing the dynamic ones set by libvirt so you must do this in maintenance mode followed by a full host restart after following those instructions.
I'm open to suggestions and feedback.