> On 29 Jul 2025, at 09:30, Marc Haber <mh+systemd-de...@zugschlus.de> wrote:
>
> Hi,
>
> I have a template service unit which runs a oneshot service that generates
> both high CPU and high I/O load for a couple of minutes. The service is
> templated a couple of times and runs from an, also templated timer.
>
> In another use case, I have independent services that generate high CPU and
> high I/O.
>
> In both cases, it has been measured that total processing time is quicker
> when one lets the jobs run one after the other instead of having them
> conurrently compete over same set of resources. The measurement results are
> even more clear when the data is stored on HDDs due to head movement and disk
> rotation latency.
>
> I would like to lock them against each other that only one of those services
> runs concurrently at a time, and other instances that might have been
> requested while one is still running are delayed until everyhing is "free".
> Missing a job because one other is already running would be a bug.
>
> The solution one finds on the net is to use flock(1) in the ExecStart*
> options, often making wrapper scripts necessary. I find this clumsy and
> un-systemd-like and would not like to do that.
>
> Does systemd offer a better solution for this?
Is it possible to use After= or Before= in template services to order them?
That is what you would do for non-template services normally.
Barry
>
> Greetings
> Marc
>
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