[systemd-devel] Doc issue: does BindsTo wait for a service to become active?

[Andrei Borzenkov]

23.06.2025 08:00, Christopher Hunt wrote:
> Howdy,
> 
> I’m looking for some clarification on BindsTo as I’m wondering if there’s some clarification required in the doc (1). I think I’m perhaps misinterpreting what the doc is referring to as “active" i.e:
> 
> "When used in conjunction with After= on the same unit the behaviour of BindsTo= is even stronger. In this case, the unit bound to strictly has to be in active state for this unit to also be in active state."
> 
> The key word here is “active” and perhaps mistakenly, interpret the above that a dependent service will have its starting deferred. To explain:
> 
> Given a service A set up as a notification service i.e.:
> 
> 	Type=notify
> 	NotifyAccess=all
> 
> …and this service takes a few seconds to signal that it is active via:
> 
> 	systemd-notify —ready
> 
> …and we have service B binding to it:
> 
> 	After=A.service
> 	BindsTo=A.service
> 
> I see a Job B.service/start failed with result ‘dependency’ on startup.
> 
> Shouldn’t systemd cause the start of B to wait until the systemd-notify conveys that A is ready i.e. active?

How A.service and B.service are started exactly?

> I’d like to offer updating the doc upon clarification.
> 
> Thanks.
> 
> Kind regards,
> Christopher
> 
> (1) https://www.freedesktop.org/software/systemd/man/latest/systemd.unit.html
> 
>