drbd-graceful-shutdown.service interfering with Pacemaker

[Lars Ellenberg]

On Thu, Jan 23, 2025 at 12:56:11PM -0800, Reid Wahl wrote:
> Hi, we at Red Hat received a user bug report today involving drbd and Pacemaker.
> 
> When shutting down the system (e.g., with `shutdown -r now`),
> Pacemaker hangs when trying to stop the cluster resource that manages
> drbd. If the user manually stops Pacemaker before shutdown (e.g.,
> `systemctl stop pacemaker`), the problem does not occur.

So apparently we forgot to add a "Before=pacemaker.service"
or even better "Before=resource-agents-deps.target"
to the graceful shutdown service.

If you don't need it in your environment, you can still "mask" it.

I have some changes queued up for our systemd thingies,
I'll work that in as well.

BTW, stopping pacemaker explicitly first should be a generic recommendation
and has proven useful in many cases.
Because all sorts of missing dependencies for all sorts of things, which,
because of the racy nature, only "sometimes" are stopped "too early".

And because, whenever there is a problem during shutdown of pacemaker,
for whatever reason, and you already initiated the system shutdown,
you have very limited means to "help it along", and sometimes need to
wait out all of the timeouts and escalation timeouts.

Thank you for the report.

    Lars