[CentOS-devel] Balancing the needs around the CentOS platform

Sat Dec 19 21:25:54 UTC 2020
Mark Mielke <mark.mielke at gmail.com>

On Sat, Dec 19, 2020 at 4:15 PM Gordon Messmer <gordon.messmer at gmail.com> wrote:
> On 12/19/20 9:49 AM, Nico Kadel-Garcia wrote:
> > On Sat, Dec 19, 2020 at 12:29 PM Matthew Miller <mattdm at mattdm.org> wrote:
> >> It's important to note that the CentOS Linux rebuild never actually had
> >> this. RHEL minor releases are actually branches, and you can stay at a minor
> >> release and still get security updates. For CentOS Linux, a minor release is
> > No. RHEL minor releases are more like source control "tags" than
> > branches.
> I promise: You do not understand RHEL better than Matthew Miller does.
> Just stop for a moment and listen to him.  You might learn something new.

This is false. Nico is describing a similar system to what we do.

> CentOS point releases are more like source control tags than branches.
> If you have only used CentOS and not RHEL, then I can see why you might
> be confused about this point.  You are accurately describing CentOS.

This is false. I don't think you understand the RHEL release process.
Check my other post. Red Hat has internal branching that you were
unaware of (apparently), and CentOS is using the later branch, not the
earlier branch. You can clearly see when this happens when RHEL names
the package ".el7_6" for a package that is newly introduced in RHEL
7.6. Normally, they just use ".el7" if it is in the latest branch, but
if they backport to the branch that CentOS picks up, it shows up as
".el7_6" in the RHEL repositories.

> RHEL, however, branches at point releases.  You can pin an RHEL host to
> a specific point release and continue to get only security and bug
> fixes, and no new features (which are introduced only at point
> releases).  You can't do that with CentOS, because there's only one branch.

This is partially false. Red Hat branched *before* the point releases,
and CentOS picks these up. However, Red Hat also continues with EUS
branches *after* the next minor release is cut.

> The difference is the same as source control.  When you check out a
> branch, you're going to get content not at a specific point in time, but
> all of the latest changes to that branch since it was made.  That's what
> you'll get from RHEL if you install a specific point release, pin it,
> and apply updates.  It's meaningful and supported to have an RHEL 7.5
> host today.  That host can be fully up to date and secure, and still be
> running the 7.5 branch.  When you check out a tag, however, you're
> getting a specific point in time and no change since.  That's what you
> get when you install an old CentOS point release.  CentOS point releases
> don't really have any other meaning.  If you have a host running
> 7.5.1804, that just means that you've stopped applying updates, and
> that's not supported by anyone.

This conclusion is false. It is ignoring that Red Hat branched prior
to the cut of the release, before CentOS saw it, and it is ignoring
that Red Hat maintains the branch accessible to CentOS until after the
next release is cut.


-- 
Mark Mielke <mark.mielke at gmail.com>