Ovirt upgrade from 4.1 to 4.2

yum clean all
yum install http://resources.ovirt.org/pub/yum-repo/ovirt-release42.rpm
yum-config-manager --save --setopt=ovirt-4.1-centos-gluster38.skip_if_unavailable=true
yum-config-manager --save --setopt=ovirt-centos-ovirt41.skip_if_unavailable=true



And finally:

yum update