Re: Message about ntp when updating
Chris Davies wrote, on 01/12/12 00:12:
> Jörg-Volker Peetz <jvpeetz@web.de> wrote:
>> Here I'm using "rdate -an" in a cron job with something like the following
>> rdate -acnv $NTPHOST
>
> Just like ntpdate or any of the other cron based solutions proposed in
> this thread, this does not train the clock. So although rdate slews the
> clock, it doesn't train it to become more accurate over time. NTP does
> all this out of the box - and you get multiple server resiliency from
> the NTP Pool.
>
> (Do you really need the -c flag to rdate? My systems don't.)
>
> Chris
>
>
Now that you mentioned it, I checked again for the "-c" option. Indeed, it
screws the clock by approx. 23 sec. (using de.pool.ntp.org). As the man page for
rdate states, comparison with a radio controlled clock revealed this.
Thank you very much for the hint.
I'm using rdate because it's a small uncomplicated (nearly :-) package.
And yes, calling rdate every 8 hours I see an approx. constant adjustment value
in the log file.
--
Best regards,
Jörg-Volker.
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