[systemd-devel] Why does sysv generator translate Required-Start keyword into an After= ordering dep only ?

[Francis Moreau]

On Tue, Mar 8, 2016 at 7:51 AM, Andrei Borzenkov <arvidjaar at gmail.com> wrote:
> 07.03.2016 10:04, Francis Moreau пишет:
>> Hello,
>>
>> Sorry for the long delay.
>>
>> On Fri, Feb 26, 2016 at 5:05 AM, Andrei Borzenkov <arvidjaar at gmail.com> wrote:
>>> 26.02.2016 00:55, Francis Moreau пишет:
>>>>
>>>> But now I'm wondering how the following case is handled: a sysinit
>>>> script "a" has "Required-Start: b". But "b" is a native systemd
>>>> service. I don't think the tool that enable/disable sysv services can
>>>> enable and order correctly the native service.
>>>>
>>>
>>> What difference does it make?
>>
>> The difference is that in my current understanding nothing will pull "b" in.
>
> That was answered in part you trimmed off. sysvinit never actively
> pulled "b" in either so nothing really changed here.
>

In my understanding insserv is part of the sysvinit implementation.

Therefore to enable a service with sysvinit, we do:

 - insserv a (this will create S<xx>a *and* S<yy>b" with yy < xx)
 - init will start *both* a and b

However with systemd and 'b' being a native unit:

 - insserv a (this will create S<xx>a only)
 - systemd will only start a

-- 
Francis