We are happy to inform you, that we have prepared Essex RPM packages for RHEL and Centos. We tested packages for compatibility with Scientific Linux as well. For Centos you should also use EPEL repository.
RHEL yum repo: http://yum.griddynamics.net/yum/essex/.
Centos yum repo: http://yum.griddynamics.net/yum/essex-centos/
$ yum install openstack-nova-essex-node-full
and then follow instructions from http://openstack.griddynamics.com/setup_single.html (starting from step 3).
We are waiting for your questions/comments at our mailing list: firstname.lastname@example.org.