Le 18/04/2016 17:17, Rainer Weikusat a écrit :
> Didier Kryn <kryn@???> writes:
>
> [...]
>
>> The problem is the way the ntp service is started in Debian involves
>> invoking ntpdate prior to ntpd.
> While remember this, I've checked installations of Debian 7, 6 and 5 and
> none of them did this (anymore). The ntpd manpage also says
>
> -q Exit the ntpd just after the first time the clock is set.
> This behavior mimics that of the ntpdate program, which is to be
> retired.
>
>> This can't work with the method of starting all services in the same
>> time, in general, not specifically by systemd.
> It absolutely can: This depends on how often the stub resolver in the C
> library (or the systemd stub resolver) retries a query before giving
> up. If this interval made up of this is longer than any actually
> experienced 'network failure' (this is - of course - impossible as 'the
> internet' is composed of many computers and at least some of them are
> unusable at any given time), it will "work", otherwise, a user might
> become aware of the network failure. But this can (cf remark about 'many
> computers') really happen at any given time while a system is up and not
> only during startup.
>
> Fittingly, my 'internet connection' broke down while writing
> this. Turning the router on before anything else and waiting until it
> signals 'connected' is no cure for that.
>
ntpd running as a server can wait until the network is ready. But
if you run it with the option -q, you expect a different behaviour,
like, maybe, a quick termination.
Didier