[CentOS-devel] VDO on CentOS Stream

Wed Sep 25 19:39:53 UTC 2019
Andrew Walsh <awalsh at redhat.com>

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