error: Failed to reconnect to the hypervisor
error: no valid connection
error: Failed to connect socket to '/var/run/libvirt/libvirt-sock': No such file or directory

Further investigation found avahi was needed for this to work. The final fix was running



yum -y install avahi
/etc/init.d/messagebus restart
/etc/init.d/avahi-daemon restart
/etc/init.d/libvirtd restart
/sbin/chkconfig messagebus on
/sbin/chkconfig avahi-daemon on