In the second to third quarter of 2014 we moved our infrastructure from a traditional "single full server for cPanel" environment to a virtualized environment. Traditionally cPanel would be installed on a server and take up that entire server alone. If that server, for example, was showing signs of system failure then the only way to migrate the data and accounts would be by deploying a new server and reinstalling everything from scratch. We would then need to manually transfer data across for individual accounts, update all accounts to new IP addresses, update DNS, contact users advising them of the change and so on. Typically in this situation, migrations can take many days and even up to several weeks - particularly in situations where clients need to update their DNS. It is particularly worse in cases where we do not manage the DNS and clients have to update it manually via a third party.
Differences in Virtualization
In virtualization, containers are created within the server and are isolated from each other. Think of this like separating a server into pieces. Each piece exists on its own and is cut off from the other pieces (for the most part), but the pieces are still powered by the server itself.
Because all of the configuration, data and settings exist within the container and not the underlying server, we have significantly more flexibility. We are able to move containers from one server to another without any changes to IP addresses, DNS or any other configurations - these settings are carried over from the container. If server hardware changes in the future and we want to take advantage of faster processors, faster and larger hard drives, or anything else for that matter - we can simply move the container to a higher powered server rather than having to reinstall everything from scratch and move data across manually and one account at a time.
To give you an idea of the time savings; we are able to move an entire container across from one server to another in a matter of hours, rather than the many days it takes to deploy a new server from scratch and move accounts manually one at a time.
So what does this mean for me, and why is it showing "VPS Optimized" on my cPanel?
From an end-user perspective this means nothing for you. cPanel will behave the same way that you are used to and everything will operate exactly as you expect. The reason you are seeing "VPS Optimized" at the top of your cPanel is simply because cPanel is running within a virtualized container.