[CentOS] Admins supporting both RHEL and CentOS

Wed Nov 29 12:21:27 UTC 2017
Peter Eckel <lists at eckel-edv.de>

Hi Joseph, 

> On 28. Nov 2017, at 14:06, Joseph L. Casale <jcasale at activenetwerx.com> wrote:
> With a few exceptions, I see most admins treat CentOS as a single rolling release and rely on the ABI commitment assuming things just work between point releases. On the other hand I see the opposite with RHEL where admins constrain installations to the point release.

I concur with the latter: I also often see RHEL installations where the admins assume they are running "RHEL 7.3" rather than "RHEL 7". In some cases there isn't even an upgrade mechanism in place: Systems are installed from ISO images (usually by the solution vendor) and there are no upgrades whatsoever until the system gets decommissioned.

While that may seem a bit strange insofar as the upgrade mechanism with RHEL works quite the same as with CentOS by default (running updates regularly will make RHEL cross .x boundaries when they are reached), the different behaviour might come from three facts: 1. some vendors restrict their support to specific .x releases, 2. RHEL systems tend to run in production environments more often than CentOS systems, so they are subject to stricter rules regarding testing and clearance of updates, and 3. maintaining a RHN satellite or allowing internet access for RHN-registered systems is not part of the enterprise's IT strategy (don't laugh).

> What is the case with users on this list who support both?

I for my part treat RHEL and CentOS basically the same with respect to upgrades wherever possible: The test stages are quite near to the current bleeding-edge release (if that expression is not too far-fetched for an enterprise distribution), and after successful testing (usually a couple of weeks to a month, with the exception of security updates which are higher prioritised) they go into production.