Re: Strange ntpmon offset

[Massimiliano Fago]

>
> Yo Massimiliano!

Ciao Gary,
it's always a pleasure to hear from you.

> > gpsd: 3.22 (revision 3.22)
>
> Almost 2 years old.  3.23.1 is current.
>
> > ntpmon ntpsec-1.2.0+ 2021-04-20T14:25:51Z (git rev 1feb8f90d)
>
> Better, but 1.2.1 is current.

ok, I will update its

>
> > my gps is u-blox and I have an external antenna. MAX-M8Q-0
>
> Good enough for timekeeping.
>

yes, I followed your suggestions

> >
> > refclock shm unit 1 minpoll 4 maxpoll 4 refid PPS flag4 1 prefer
> > # GPS Serial data reference (NTP0)
> > #server 127.127.28.0 minpoll 4 maxpoll 4
> > #fudge 127.127.28.0 time1 0.9999 refid GPS
> > refclock shm unit 0 time1 -0.0900 refid GPS flag4 1 noselect
>
> Where are the other chimers?  ntpd will not work with just 1 chimers.
> You ntp.conf is missing the pool statement.

This is my full ntpd.conf:

#pool us.pool.ntp.org iburst

#driftfile /var/lib/ntp/ntp.drift
#logfile /var/log/ntp.log

restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1 mask 255.255.255.0
restrict -6 ::1

# GPS PPS reference (NTP1)
#server 127.127.28.2 minpoll 4 maxpoll 4 prefer true
#fudge 127.127.28.2 refid PPS
##fudge 127.127.28.1 flag1 1
refclock shm unit 1 minpoll 4 maxpoll 4 refid PPS flag4 1 prefer

# GPS Serial data reference (NTP0)
#server 127.127.28.0 minpoll 4 maxpoll 4
#fudge 127.127.28.0 time1 0.9999 refid GPS
refclock shm unit 0 time1 -0.0900 refid GPS flag4 1 noselect

#MFA aggiunto il 30/09/2019
#server 127.127.43.0     # standard Linux RTC

#Log
driftfile /var/lib/ntp/ntp.drift

statsdir /var/log/ntpstats/

statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable

logfile /var/log/ntpd.log
logconfig =syncall +clockall +peerall +sysall

Can you suggest a good ntpd.conf file for my application?

>
> > My problem is that I have strange value on offset data.
>
> Dunno why you think that is strange.  Your ntpd is not locked, so it not
> driving your local clock, so the offset will vary randomly with temperature

my fear is that the system clock changes randomly. Can it be possible?
I need a stable and precise time.

>
> > Please give me some suggestion.
>
> RTFM:
>
> https://gpsd.io/gpsd-time-service-howto.html
> https://gpsd.io/gpsd-time-service-howto.html#_feeding_ntpd_from_gpsd
> https://gpsd.io/time-service-intro.html
>
>
> RGDS
> GARY

OK, grazie!