systemd clarification

[Bruno Cornec]

Hello,

/etc/systemd is used to override or add locally units which are not delivered as part of the std systemd delivery which is under /lib/systemd (or /usr/lib/systemd depending on Linux distribuions). It's an easy way to modify a std unit file and change say the options used to start the daemon e.g.
So:

Mike Jones said on Tue, Aug 25, 2020 at 10:20:54AM -0600:
>The lib path is not a search path in the systemd documentation, and the etc path has links into the lib path. So I assume services in the lib path are only run if they are linked into the etc path. Is this correct?

No. they are run if they are enabled (systemctl list-units to see that)

>If there is a an After= that lists something found only in the lib path, I assume it will run because After is not strong enough to prevent start. But if it was Requires=, then I assume it cannot start unless it is linked into the etc path so that it is available. Is this correct?

No. No link is necessary. 

Best regards,
Bruno.
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