[systemd-devel] Implicit unit dependency on slice might be too weak ?

[Francis Moreau]

Hello,

On Mon, Sep 21, 2015 at 7:43 PM, David Herrmann <dh.herrmann at gmail.com> wrote:
> Hi
>
> On Mon, Sep 21, 2015 at 4:50 PM, Francis Moreau <francis.moro at gmail.com> wrote:
>> Hi,
>>
>> If a unit depends on a slice, a Wants=machine.slice is automatically
>> added to the unit constraints.
>>
>> Why is "Requires=machine.slice" not prefered instead ?
>
> Usually "Wants=" is preferred as it makes the units more fail-safe.
> Especially for slices, I cannot see why "Requires=" would be
> beneficial. If a specific unit needs this, a simple
> "Requires=foobar.slice" gets you what you want.
>

But what if the slice fails to start ?

Will the unit asking for a specific slice (which fails to start) be
moved into another slice ? It seems that whatever the final
destination used by systemd, the constraints used by the "fallback"
slice won't be correct, no ?

Thanks
-- 
Francis