[CentOS-devel] Centos 8.x, dlm Package unavailable

Josh Boyer

jwboyer at redhat.com
Wed Sep 16 11:41:10 UTC 2020

On Fri, Aug 28, 2020 at 7:58 AM Judd O'Bannon via CentOS-devel
<centos-devel at centos.org> wrote:
> > On 8/25/20 11:21 AM, Theodor Mittermair wrote:
> >> Hello,
> >>
> >> I'd like to inquire about the status of the "dlm" package on Centos 8,
> >> which is required for using 'lvmlockd', replacement of 'clvmd'.
> >> I also asked on #centos irc channel and was directed to this mailing list
> >> There is a corresponding bug ticket [2] for this issue for quite some
> >> time, but since the end-of-life of CentOS 6 grows closer, some people
> >> would like to replace their CentOS 6 Cluster with a CentOS 8 one, which
> >> is why I ask on this mailing list now.
> >>
> >> With the release of CentOS 8.0 it seems there were some issues with
> >> HighAvailability in general [1], but seem to have been resolved with
> >> CentOS 8.1.
> >>
> >> However, as already mentioned there is a separate ticket [2], for the
> >> dlm package, which is unresolved as far ( 2020-08-25, Centos8.2 ) as i
> >> am aware.
> >> This prevents the use of clustered lvm and gfs2 out of the box, not an
> >> uncommon use when configuring a HA Cluster, also described by RedHat
> >> documentation [3].
> >> In that tickets' conversation, it is mentioned that "that package is not
> >> in RHEL .. we have released what is in RHEL", however someone else
> >> seemed to have been in contact with RedHat and received information that
> >> "...this package is in fact part of a RedHat repository and then CentOS
> >> members should be able to take a look into it again...".
> >>
> >> I'd also like to bring attention to the following explicitly:
> >> * dlm-lib and dlm seem to be built from the same source rpm, dlm-lib is
> >> available while dlm is not.
> >> * apparently at some point in time dlm could be downloaded from koji
> >> [4], but no more. For testing purposes we built dlm ourselves, locally
> >> as well as on copr [5], which seems to work thus far.
> >> * fedora (however much this might mean) provides dlm.
> >> * It might just be a configuration error on the build system, if I
> >> understood correctly, there was/is larger amounts of restructuring. Also
> >> see chders' post from 2020-08-21 [2], which provides a possible
> >> explanation and solution.
> >>
> >> For completeness, you should be able reproduce the absence of that
> >> package with:
> >> "yum --disablerepo='*'
> >> --enablerepo=BaseOS,AppStream,HighAvailability,epel,cr,centosplus,PowerTools,Devel,extras,fasttrack
> >> list available | grep dlm"
> >> or simply attempt to
> >> "yum install dlm"
> >> on your CentOS 8.x Installation.
> >>
> >> Therefore, I would like to ask:
> >> Is this an error on my end, am I doing something wrong or missing a
> >> configuration?
> >> If no, is there actually any political/technical/administrative/law
> >> based reason for the unavailability of the "dlm" package?
> >> If no, according to recent posts on the ticket [2], there might be a
> >> rather simple solution (simplified, declaring the package to be included
> >> in a repository), is it valid and who could do this if applicable?
> >>
> >> with best regards
> >> Theodor Mittermair
> >> <https://koji.mbox.centos.org/koji/buildinfo?buildID=4801>
> >> [1] https://bugs.centos.org/view.php?id=16553
> >> [2] https://bugs.centos.org/view.php?id=16939
> >> [3]
> >> https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_high_availability_clusters/assembly_configuring-gfs2-in-a-cluster-configuring-and-managing-high-availability-clusters
> >> [4] https://koji.mbox.centos.org/koji/buildinfo?buildID=145
> >> [5] https://copr.fedorainfracloud.org/coprs/astra/dlm/
> >>
> >>
> >> _______________________________________________
> >> CentOS-devel mailing list
> >> CentOS-devel at centos.org
> >> https://lists.centos.org/mailman/listinfo/centos-devel
> >>
> > Hi Folks,
> >
> > Some clarity will follow on how we plan to deliver Addon repositories
> > like ResilientStorage, HighAvailability and NFV.
> >
> > Because of Red Hat’s desire to develop Addons along with the next minor
> > release of RHEL our plan is to enable ResilientStorage and NFV in CentOS
> > Stream for direct consumption.
> >
> > If you think a package belongs in another repository, we encourage you
> > to open a CentOS Stream bugzilla to discuss with RHEL maintainers:
> >
> > https://bugzilla.redhat.com/enter_bug.cgi?product=Red%20Hat%20Enterprise%20Linux%208&version=CentOS%20Stream
> >
> > We do not plan to expand the portfolio of Addons for CentOS Linux.
> >
> > If there is a group of interested folks who wish to maintain extra
> > content built against CentOS Linux, you may apply for a Special Interest
> > Group: https://wiki.centos.org/SIGGuide
> >
> > Cheers!
> > --Brian
> My apologies as I just subscribed to this list, I'll likely break the thread up. I did my best to contain relevance above.
> First question, the statement ""...Resilient Storage is not base...". There has been a shift from 7 to 8 that I don't understand. RHEL 7 provides dlm in ResilientStorage, then CentOS 7 provides dlm in base [1]. The dlm package is still part of ResilientStorage in RHEL 8, but can't be provided?  I wasn't able to find any answer to why that was changed. Can you provide any insight to the shift?

RHEL 7 does not provide dlm in base, and that is indeed a disparity
between RHEL 7 and CentOS 7.  I can perhaps provide some context as to
how that happened.

In RHEL 7.2, the dlm-lib subpackage was added to the main repositories
to satisfy dependencies added to other packages.  The dlm package
itself remained in the Resilient Storage AddOn, as RHEL only supports
dlm with that AddOn and under specific  configurations.  As a result
of the dlm-lib subpackage being moved to the mainline repository, the
SRPM for dlm was delivered to CentOS as required.  My guess is that
context for this was not communicated and CentOS built and delivered
the package as a whole.  Once the disparity was noticed, it is likely
that it was retained so as to not be disruptive to CentOS users.

> Second question, the current advice seems to be "dlm will be in centos-stream and you should use that." However, tdawson made a pretty explicit statement: "If people are running their production machines on CentOS Stream ... well, in my opinion, that's their problem."[2] These statements appear contradictory.

They do, somewhat.  That's partly because one is fact and one is opinion :)

Brian's statement on where the focus for AddOn repository content will
be in the broader 8 ecosystem is 100% accurate.  They will be
available in CentOS Stream.

Using CentOS Stream in production is actually something that has a
number of factors to it.  CentOS Stream reflects the next RHEL release
in development and provides availability to newer features and fixes
as they are developed.  However, like all in-development code bases,
Stream will occasionally have bugs.  Your deployment types, risk
tolerances, and ability to self-service issue resolution all factor
into what you use in production.  Some people use Fedora in
production, some rely on the value that a RHEL subscription brings for
production workloads.

> Just trying to piece this all together so I can explain to my peers the business and community decisions going on here.
> Currently someone that set up a cluster with gfs2 in 7 can't do the same thing in 8 due to the dlm package missing. That is a loss of functionality and seems to indicate it's a bug or intentional reduction in feature set.

It's a bug in CentOS 7 that was kept unfixed.  The feature set from
RHEL 7 and RHEL 8 remains consistent, with it only being available in
the Resilient Storage AddOn.


> If I'm misunderstanding any of this please educate me.
> Thank you,
> Judd
> [1] http://mirror.centos.org/centos-7/7/os/x86_64/Packages/dlm-4.0.7-1.el7.x86_64.rpm
> [2] https://lists.centos.org/pipermail/centos-devel/2020-July/037034.html
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