Have you ever wondered how people plan for the capacity of a system? This presentation tries to explain how to do it. It is definitely an art, but the tools used here will help you learn how to do it with logic and reason rather than hopeful optimism. That should help you keep from under or over sizing the systems you build in the future.
Systemd is the new system that Ubuntu is using to control the boot process. It's what makes the systems boot faster and cleaner. It does things dramatically differently than the older init.d system did.
If you company is running Redhat having your own local package repo is one of the best ways to control your environment. It allows you to update the Repo on your schedule. Then when you update your systems they are all updated to the same level. (Assuming you don't upgrade it in between servers.) Since Redhat updates the repos multiple times a week. You now can get everything upgraded without introducing new packages in the middle of your cycle. This article gives you a quick walk through to get one setup. Then the only thing you need to do is point your systems to use it rather than the main RedHat Repos. This will also help speed up updates since your LAN speed will most likely exceed your Internet Connection.