[systemd-devel] mdmon at md127 is stopped early

[Mariusz Tkaczyk]

On Thu, 10 Feb 2022 11:49:30 +0100
Lennart Poettering <lennart at poettering.net> wrote:

> On Mi, 09.02.22 17:16, Mariusz Tkaczyk
> (mariusz.tkaczyk at linux.intel.com) wrote:
> 
> > It is probably wrong, but it worked this way for many years:
> > "Again: if your code is being run from the root file system, then
> > this logic suggested above is NOT for you. Sorry. Talk to us, we can
> > probably help you to find a different solution to your problem."[3]
> >
> > How can I block the service from being stopped? In initramfs there
> > is a mdmon restart procedure, for example in dracut[4]. I need to
> > save mdmon process from being stopped.
> >
> > I will try to adapt our implementation to your[3] suggestions but
> > it is longer topic, I want to workaround the issue first.
> >
> > [1]https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git
> > [2]https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git/tree/systemd/mdmon@.service
> >  
> 
> So with that unit systemd shouldn#t stop it the service at all, given
> that you set DefaultDependencies=no.
> 

> It would be good to figure out why it is stopped anyway. i.e. check
> with "systemctl show" on the unit what kind of requirement/conflicts
> deps there are which might explain it.
> 

> Otherwise there might simply be another program that explicitly tells
> systemd to shut this stuff down, i.e. some script or so. Turn on debug
> logging (systemd-analyze log-level debug) before shutting down, the
> logs should tell you a thing or two about why the service is stopped.
> 

That is ridiculous when I enabled debug logging by command provided, it
is not killed:

[  OK  ] Stopped Avahi mDNS/DNS-SD Stack.
[  OK  ] Stopped irqbalance daemon.
[  OK  ] Stopped NTP client/server.
[  OK  ] Stopped libstoragemgmt plug-in server daemon.
[  OK  ] Stopped Machine Check Exception Logging Daemon.
[  OK  ] Stopped Self Monitoring an…ing Technology (SMART) Daemon.
[  OK  ] Stopped Modem Manager.
[  OK  ] Stopped CUPS Scheduler.
[  OK  ] Stopped Enable periodic up… of entitlement certificates..
[  OK  ] Stopped OpenSSH server daemon.
[  OK  ] Stopped Deferred execution scheduler.
[  OK  ] Stopped Command Scheduler.
[  OK  ] Stopped Getty on tty1.
[  OK  ] Stopped Serial Getty on ttyS0.
[  OK  ] Stopped Software RAID monitoring and management.
[  OK  ] Stopped PackageKit Daemon.
[  OK  ] Stopped Load/Save Random Seed.
[  OK  ] Stopped Session 4 of User root.
[  OK  ] Stopped Session 1 of User root.

I was able to step down into systemd-shutdown. Probably, I caused it
during debugging (I modified mdmon at .service and reinstalled mdadm
package many times). Are you able to explain what happens?

Anyway, thanks for help. Now I can move forward. I will open separate
thread (if necessary) for other problems because they will be related
with systemd-shutdown.

Thanks,
Mariusz