I’ve recently installed certbot to create an SSL certificate for my one of the websites on my server. Now Virtualmin is telling me that my OS is CentOS 6.3 but I’m REALLY running CentOS 6.1. Well, I always thought my OS was CentOS 6.1. Where does it get the weird idea I’ve upgraded to 6.3? Should I click that scary button labelled “Update Detected Operating System”, or if I do so will the sky fall down and we’ll all be murdered in our beds?
A yum update can change CentOS minor version. That’s a good thing. You need to regularly your OS to stay on top of security updates. Note that it won’t change major versions (and there is no easy way to upgrade from CentOS 6 to CentOS 7+), and CentOS 6 reaches end of life in June, so you need to be planning for a migration to CentOS 7 or CentOS 8.
And, yes, just click the button to update the detected OS. What makes it seem scary?