Hi,
as announced and scheduled, several centos services are going to be out of service for about 48 hours since March 14th, 13:00 UTC:  
https://seven.centos.org/2017/03/infra-scheduled-major-outage-for-several-services/

The list of involved services includes https://cbs.centos.org (Koji).
Our stable release tracker rpm ( http://resources.ovirt.org/pub/yum-repo/ovirt-release41.rpm ) requires packages from there and so oVirt from stable release is currently not installable as well on Centos based systems.

[centos-ovirt41-candidate]
name=CentOS-7 - oVirt 4.1
baseurl=http://cbs.centos.org/repos/virt7-ovirt-41-candidate/$basearch/os/
gpgcheck=0
enabled=1

[centos-ovirt-common-candidate]
name=CentOS-7 - oVirt common
baseurl=http://cbs.centos.org/repos/virt7-ovirt-common-candidate/$basearch/os/
gpgcheck=0
enabled=1

We are trying to find a recovery solution.