Re: [chrony-users] Multiple interfaces is possible?

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On Wed, Sep 14, 2016 at 11:49:02AM +0000, Jahagirdar, Bhushan wrote:
> From your reply below it seems to me that at least 48 sec would be
> needed for Chrony to lock on a source and set the time for that one
> source. If there are multiple sources then it would be multiple of
> 48 sec?

No, the sources are polled in parallel. If they are all configured
with the same polling interval, the time needed to make the first
update of clock after start wouldn't change.

> What if there is stringent requirement that the time should be set within 1-2 secs in a typical embedded system.
> Then is there any specific configuration that can help achieve this with Chrony?

You can shorten the refclock polling interval (the poll option) to
reduce the time as needed. But 1-2 seconds will be possible only if
the SOCK refclock can make multiple measurements per second. With 1
measurement per second the best you can do is 3 seconds (poll 0). Note
that if there is only one measurement per poll, the median filter will
be effectively disabled and the synchronization will be very sensitive
to errors in the measurements.

Miroslav Lichvar

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