Most people getting started with OpenStack have learned that it can be hard to install. As they continue to explore, they soon learn that it isn't easy to un-install and re-install either.
During the course of developing our OpenStack management solution, we've discovered that being able to swiftly un-install and re-install OpenStack can, in some situations, be almost as important as successfully managing it.
To make removal and re-installation of OpenStack as easy as possible, we have built a dedicated removal utility which goes through the individual items composing an OpenStack deployment and asks the user which ones are to be removed. The utility makes sure that all relevant leftover files/objects from the previous deployment have been removed and will not impact any subsequent deployment. Once the entire OpenStack deployment has been wiped clean, re-installing OpenStack is a snap.
Our OpenStack (re-)installation process also tries to be smart about what it does. The individual stages of the installation can be considered independent, so even if you stop the installation mid-way, you can usually restart the re-installation process from scratch and still have it complete successfully (without having to clean up the half-deployed mess yourself).