What is Best Practice for Upgrading a Distro?
So, I'm using CentOS 6 and need to upgrade to 7. What's the best way to do this with minimal downtimes?
So I want to say right off the bat that we generally recommend against inline upgrades, as they do have a tendency to cause unexpected issues.
My suggestion would be to deploy a new Linode with CentOS 7, copy over your files and configurations with a tool like rsync and once you have verified that everything is working properly swap IPs between the original Linode and the new one. This will help ensure stability and minimal downtime as your original Linode will still be up and running until you are ready to cut over to the new one with CentOS 7.