[CentOS-devel] VDO on CentOS Stream

On Wed, Sep 25, 2019 at 12:53 PM Andrew Walsh <awalsh at redhat.com> wrote:
>
> On Wed, Sep 25, 2019 at 3:47 PM Brian Stinson <brian at bstinson.com> wrote:
> >
> > On Wed, Sep 25, 2019, at 14:39, Andrew Walsh wrote:
> > > Hello,
> > >
> > > First, let me express how excited I am by the news of the CentOS
> > > Stream offering.  I am really looking forward to how this works out in
> > > the long run.
> > >
> > > I am in the group that builds VDO, and it is currently delivered as a
> > > kmod in CentOS Stream, RHEL, and CentOS.  This requires that if the
> > > signatures of the symbols that VDO uses change from one kernel to the
> > > next, we may need to rebuild the package against the more recent
> > > kernel.
> > >
> > > The current version of kmod-kvdo (6.2.0.293-50.el8) delivered in
> > > CentOS Stream is the equivalent of the RHEL-8.0/CentOS-8.0 GA, while
> > > the version of the kernel (4.18.0-144.el8) is newer.  In the time
> > > between the kernel that kmod-kvdo was built against (4.18.0-72.el8)
> > > and the current kernel in CentOS Stream, the signatures have changed.
> > > As a result, the kernel modules delivered in the kmod-kvdo package
> > > cannot be loaded due to symbol mismatches (all device mapper related
> > > symbols that change periodically, from what I've experienced).
> > >
> > > I believe that a simple rebuild of kmod-kvdo-6.2.0.293-50.el8 against
> > > kernel-4.18.0-144.el8 should be effective enough to get it working
> > > again.
> > >
> > > How can I help facilitate this rebuild now and/or moving forward?  I
> > > realize that things are still very much in motion and not fully
> > > implemented/decided at this point.
> > >
> > > Andy Walsh

> It would actually happen from
> https://git.centos.org/rpms/kmod-kvdo/tree/c8 since the vdo package
> just provides the user space libraries and utilities.
>
> >
> > or are there changes needed?
>
> The only changes that should be needed (though I haven't tested it to
> be 100% certain), is to update the required kernel to make sure it
> builds against the proper kernel and also bump the Release field in
> the spec from 53 to 54 to get a new NVR.
>
> Change line 4
> %define spec_release 53
> To:
> %define spec_release 54
>
>
> Change line 9
> %define kmod_kernel_version 4.18.0-80.10.1.el8_0
> To:
> %define kmod_kernel_version 4.18.0-144.el8

> Andy Walsh

kmod-kvdo is in the BaseOS repo, so I'd think the version for CentOS
Stream should be published in the Stream-BaseOS repo.

By the way I built kmod-kvdo against the -144 kernel and it (modprobe
kvdo) seems to work. Whether this weak-links against the next kernel
update remains to be seen.

Akemi