[CentOS] Version numbering vis a vis CentOS and RHEL

[Jonathan Billings]

On Tue, Dec 08, 2015 at 08:45:10AM -0500, Phelps, Matthew wrote:
> What I want to know is, why is CentOS doing things differently than RedHat?
> Who made this decision, and was there any consideration given to making
> such a highly visible departure? When did CentOS decide to fork away from
> RHEL? It doesn't matter if this is truly the case, or not. Perception is
> reality here; CentOS is now no longer "the same" as RHEL and this turns it
> into a whole different, new, distro of Linux. That affects things like
> software certification, hardware support, security certification, etc. etc.
> It is now a stupendous burden on those of us who chose to implement it
> because it was "the same" as RHEL.

CentOS has always been different than Red Hat Enterprise Linux,
because Red Hat is willing to support older point releases of RHEL
(for a price), while CentOS only supports the latest release.  You
might be running RHEL 7.1 Extended Update Support for another year or
so, while the rest of the world has updated to RHEL 7.2.
(see https://access.redhat.com/support/policy/updates/errata)

I believe (although I was not involved with the choice) the new naming
scheme reflects a need to advertise to the end user that there is only
one supported release of each major version of CentOS, with a regular
release of installation medium that coincides with the feature
updates that come out with each RHEL point release.

So often, I see people come on mailing lists and the IRC channels
saying "I'm running CentOS 6.1 and I can't get PHP to work" and we
have to ask why they aren't running a supported release of CentOS 6.
A lot of people seem genuinely surprised that you can't just keep
running some point release of CentOS and expect any kind of support.

I'll admit, the use of 7.2.1511 is *helpful* because then I know what
upstream version of RHEL it is based on, however, I'm also using RHEL7
along side CentOS7.  But in terms of naming the install medium, it
makes sense to just put a monotonically increasing number that
reflects a timestamp.

This is just my opinion, as both someone who tries to be helpful to
CentOS users, as well as a sysadmin in a large institution.

-- 
Jonathan Billings <billings at negate.org>