You are using RHEV2.2 right? There are no such tools for this version.
That's right, explains why I haven't been able to find 'em.
RHEV3.0 has RHEL guest agent for both RHEL5 guests and RHEL6 guest, the sources should be open in ovirt.org in the near future http://www.ovirt.org/project/subprojects/ If you use CentOS as the guest then you'll have to compile it yourself :)
Thanks, that's helpful!