[CentOS] Differences from upstream RHEL

Tue Nov 10 20:16:33 UTC 2015
Peter <peter at pajamian.dhs.org>

On 11/11/2015 09:03 AM, Edward Ned Harvey (centos) wrote:
> At work, we use some commercial software, that names RHEL6 as a
> supported OS, but not Centos6. I would like to know the difference
> between Centos and RHEL, in order to claim (or not) that we can
> support our users on Centos instead of RHEL.
> I see the release notes, that say "Packages modified by CentOS," but
> it's not clear what the modifications are. I have been browsing
> around for these details, and have not yet found specifics of *what*
> was modified in those packages.
> Can anyone please direct me toward details of what's modified in the
> packages that centos modifies? 

Mainly branding changes, as well as other minor changes to make things
work with the CentOS infrastructure, eg replacing redhat-release with
centos-release to point to CentOS package repositories instead of the
RedHat ones.

You can tell which packages were modified because they have the word
"centos" in the release number, eg: "rpm -q httpd" (use repoquery
instead of rpm if you don't have the package installed yet) shows this:

You can see better details of what has been changed by looking at the
changelog for a particular package.  CentOS changes will be at the top
of the changelog, so again using httpd as an example:
$rpm -q --changelog httpd
* Mon Aug 24 2015 CentOS Sources <bugs at centos.org> - 2.4.6-31.el7.centos.1
- Remove index.html, add centos-noindex.tar.gz
- change vstring
- change symlink for poweredby.png
- update welcome.conf with proper aliases


Note that it is possible for there to be changes that aren't listed in
the changelog, nobody's perfect.  If you want to know for sure exactly
what has changed then look up the package on git.centos.org.