[systemd-devel] systemctl start second.service first.service

[Andrei Borzenkov]

On Thu, Jan 11, 2018 at 1:59 PM, 林自均 <johnlinp at gmail.com> wrote:
> Hi folks,
>
> I have 2 service unist: first.service and second.service. I configured
> "After=first.service" in second.service. Both services are "Type=oneshot".
>
> If I execute:
>
> # systemctl start first.service second.service
>
> The ordering dependency will work, i.e. second.service will start after
> first.service.
>
> However, if I execute:
>
> # systemctl start second.service first.service
>
> first.service and second.service will start at the same time.
>

Ordering dependencies are between jobs. To have any effect here
systemd must have both start jobs queued concurrently. What is
unexpected is that multiple services are apparently submitted as
individual independent jobs, not as single "transaction". I am not
sure even if there is method to start multiple units concurrently.

> Is this behavior documented somewhere?

The systemctl behavior? Not to my best knowledge, at least explicitly.