[DRBD-user] DRBD 8.0 life cycle

[Roland Kammerer]

On Tue, Sep 21, 2021 at 07:09:49AM -0700, Paul D. O'Rorke wrote:
> I have to pass on my thanks and respect.
> 
> I have been running a 3 node "Stacked" replication set on 8.9.6 for some
> years now.  This weekend I finally bit the bullet and installed 9.11.0 from
> the Ubuntu 20.04 LTS  repos on new hardware and I am blown away at how
> simple and efficient the move was.

I'm not sure if there is some misunderstanding here...

Your kernel module (shipped with the Ubuntu kernel image) is still
in-tree DRBD 8.4. Assuming that you did not install DRBD 9.0/9.1 from
source/our PPA as well.

So to me it looks like you only updated the user-space tools (from 8.9.6
to 9.11.0). And yes, expected that that just works, we have not touched
the parts used for *kernel module* 8.4 in years by now I guess. A long
time ago we just called the next drbd-utils version 9.x instead of 8.x
to flag that we now fully support *kernel module* 9.0 (at the time, now
also 9.1). But it was just a version change without any meaning for
kernel module 8.4. We could have called the user space parts 42.23, but
the kernel module would still be 8 or 9.

Also I expect that a real kernel module switch from 8 to 9 would be that
smooth, but to me it looks like you just updated user space (and
probably the in kernel module from 8 something to 8 something else) as
part of a newer kernel.

cat /proc/drbd might clarify that a bit :)

Regards, rck