[systemd-devel] How to figure out what's causing systemd to start printing messages partway through boot?

[McKay, Sean]

Dug a little deeper and found the "(Enabling | Disabling) showing of status." debug log, which shows up exactly once in my journalctl output... but only on one type of system. I don't see it on the other (still trying to figure out if I could be hitting some sort of rate limiting).

Nothing around it seems like a failure, but I'm still digging.

Any suggestions are still welcome

Thanks!
-Sean

From: systemd-devel <systemd-devel-bounces at lists.freedesktop.org> On Behalf Of McKay, Sean
Sent: Wednesday, April 29, 2020 4:26 PM
To: systemd-devel at lists.freedesktop.org
Subject: Re: [systemd-devel] How to figure out what's causing systemd to start printing messages partway through boot?

I apparently failed to finish a sentence. Fixed. My apologies!

From: McKay, Sean
Sent: Wednesday, April 29, 2020 4:15 PM
To: systemd-devel at lists.freedesktop.org<mailto:systemd-devel at lists.freedesktop.org>
Subject: How to figure out what's causing systemd to start printing messages partway through boot?

Hi all,

Hopefully quick question:
Do you have any guidance on what I should look at to determine what is causing the show_status variable in systemd to get flipped to true without any apparent unit failures? Is there an easy way to find that information?

We have a few systems that start printing the manager status messages halfway through bootup (that aren't supposed to). They have 'quiet' set on the kernel command line and they appear to be following that for a good chunk of the boot, but partway through I start getting '[  OK ] Started...' messages without any failure showing up first (which is what I expect and have seen in other scenarios). Running 'systemctl show' after the system has booted, shows that the variable has indeed been flipped.  From looking through the code, it appears the only way this is possible should be for a unit to have hit some status other than "OK" (JOB_DONE internally, it would appear) but I don't see any of those in the output. And I'm not sure if there's an equivalent in the journal to search for.

I've poked through the journal near where things start showing up and there doesn't appear to be anything in particular that sticks out... so I turned on debug logging and there's a ton of it. And I haven't yet had any luck figuring out what I'm looking for from digging through the source code. So I figured I'd ask.

Thanks!
-Sean McKay

P.S. We're still waaaaaaay back on 229. Frantically trying to get things upgraded, but not there yet. I don't think that's relevant (I doubt this is a systemd bug), but it might come up if there's more tooling/verbosity in newer versions.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/systemd-devel/attachments/20200430/339c7156/attachment-0001.htm>