CentOS 6.2 and libvirt startup issues

After the centos 6.2 update I noticed libvirt was not running on some servers. Looking at the logs I found

Starting libvirtd daemon: 10:35:16.697: 6933: info : libvirt version: 0.9.4, package: 23.el6_2.1 (CentOS BuildSystem <http://bugs.centos.org>, 2011-12-17-16:39:59, c6b4.bsys.dev.centos.org)
10:35:16.697: 6933: error : virNetServerMDNSStart:460 : internal error Failed to create mDNS client: Daemon not running

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

In centos 6.2 restarting libvirt will not restart the vm’s. Once done libvirt was running again.