Chris's Wiki :: blog/linux/SystemdShutdownUnmountStorm Commentshttps://utcc.utoronto.ca/~cks/space/blog/linux/SystemdShutdownUnmountStorm?atomcommentsDWiki2020-05-07T15:45:21ZRecent comments in Chris's Wiki :: blog/linux/SystemdShutdownUnmountStorm.By Chris Siebenmann on /blog/linux/SystemdShutdownUnmountStormtag:CSpace:blog/linux/SystemdShutdownUnmountStorm:3eb78405a0e63b65e1df77a93392e2d9eece3c42Chris Siebenmann<div class="wikitext"><p>Our shell scripts literally run <code>mount</code> and <code>umount</code>. Systemd materializes
the .mount units on its own, and as far as I know <code>mount</code> provides no way
to make systemd modify the resulting dynamic .mount units (and anyway no
modification to an individual mount unit can prevent this).</p>
</div>2020-05-07T15:45:21ZBy Matt on /blog/linux/SystemdShutdownUnmountStormtag:CSpace:blog/linux/SystemdShutdownUnmountStorm:a369f7b3ac9c05e0dd04aeed87698972a2fbf7acMatt<div class="wikitext"><p>I'm not familiar with how your shell scripts do the mounting/unmounting, but if you have them as .mount or .service units, you can use "drop-in" config snippets to append config to them.</p>
<p>For example, suppose you have foo.service and bar.service (unit type does not matter) and you cannot (or don't want to) modify the .service config files. Instead you can add a file at `/etc/systemd/system/foo.service.d/ordering.conf` with the contents</p>
<pre>
[Unit]
Before=bar.service
</pre>
<p>and that will make the bar.service wait to start until after foo.service is started. Service stopping is done in the reverse order.</p>
</div>2020-05-07T14:45:40ZFrom 216.154.41.138 on /blog/linux/SystemdShutdownUnmountStormtag:CSpace:blog/linux/SystemdShutdownUnmountStorm:fda2ebd8785c8863795529ee784aeedb77f4f0b2From 216.154.41.138<div class="wikitext"><p>While parallelism is generally a good thing, you'd think a prudent 'limit' would be proportional to the number of processors (real or imagined/virtual) that are present on the system.</p>
<p>There's no sense kicking off off 100 processes when one only has 4 (v)CPUs or hyper-threads: yes, modern chips are very fast nowadays, but there's still a finite amount of silicon present to execute things.</p>
</div>2020-05-07T10:45:33ZBy Paul Tötterman on /blog/linux/SystemdShutdownUnmountStormtag:CSpace:blog/linux/SystemdShutdownUnmountStorm:f33bedd561651241878843cb847a787c4aa24172Paul Töttermanhttps://paul.totterman.name<div class="wikitext"><p>I didn't quite find an exact match to that issue. This is probably related: <a href="https://github.com/systemd/systemd/pull/6598">https://github.com/systemd/systemd/pull/6598</a></p>
</div>2020-05-07T07:53:31Z