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

[Francis Moreau]

On Tue, Mar 8, 2016 at 10:19 AM, Andrei Borzenkov <arvidjaar at gmail.com> wrote:
> 08.03.2016 11:33, Francis Moreau пишет:
>> On Tue, Mar 8, 2016 at 9:23 AM, Andrei Borzenkov <arvidjaar at gmail.com> wrote:
>>> 08.03.2016 11:07, Francis Moreau пишет:
>>>> 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)
>>>
>>> That would be new to me. insserv creates links ("enables") exactly those
>>> services that you specify. So if you say "insserv a" you will get only
>>> "a" enabled; this /may/ rearrange other services including "b" if they
>>> are already enabled but this will not enable "b".
>>>
>>
>> That's how I understood Lennart's excerpt I was referring to previously.
>>
>
> Hmm ... I tested on SLES11 and indeed, while "insserv a" will not enable
> "b" it will refuse to enable "a" if "b" is not enabled. And conversely
> it will not disable "b" if "a" is enabled.
>
> So at least it tries to ensure that set of enabled services is consistent.

Is this system uses systemd ?

-- 
Francis