1. Mirror a yum repository plus updates. For each day create a hardlinked directory of updates named reponame.YYYYMMDD. On the hosts you wish to update sed -i to the new day in your yum repo config file and run yum -y upgrade. When you know it works, do it on the other hosts too.
2. Use a configuration management tool like Puppet.
For your sized infrastructure you probably want the first.
Comments
You can do two things.
1. Mirror a yum repository plus updates. For each day create a hardlinked directory of updates named reponame.YYYYMMDD. On the hosts you wish to update sed -i to the new day in your yum repo config file and run yum -y upgrade. When you know it works, do it on the other hosts too.
2. Use a configuration management tool like Puppet.
For your sized infrastructure you probably want the first.
Already using puppet, and -yum, it's debian/ubuntu ;) (thanks though)