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Re: kern/53016: Clock not stable
The following reply was made to PR kern/53016; it has been noted by GNATS.
From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc:
Subject: Re: kern/53016: Clock not stable
Date: Wed, 4 Apr 2018 02:08:25 -0000 (UTC)
kivinen%iki.fi@localhost (Tero Kivinen) writes:
>ntp can keep it inside few seconds, but as the poll interval can go to
>quite big value for ntp, it can get several seconds from real time
>before ntp fixes it.
That's not how ntpd works. The clock is adjusted all the time by
running it slower or faster.
>Now one hour later the drift is already 2.7 seconds again.
>----------------------------------------------------------------------
>vielako (1:39) ~>ntpdate -q -u time1.mikes.fi
>server 194.100.49.151, stratum 2, offset 2.789676, delay 0.02701
> 4 Apr 01:39:45 ntpdate[16936]: step time server 194.100.49.151 offset 2.789676 sec
Please check with 'ntpq -p' whether ntpd actually synchronizes to
a time server. E.g.:
% ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
+time3.mikes.fi 193.166.4.57 2 u 753 1024 377 66.337 0.878 6.327
*ptbtime3.ptb.de .PTB. 1 u 466 1024 377 28.496 -0.758 0.732
+time.nrc.ca 132.246.11.231 2 u 559 1024 377 116.518 -0.451 4.356
The '*' shows the time server that is used for synchronization, a '+'
indicates verified backups.
And check with 'ntptime' the adjustment of the system time. E.g.:
% ntptime
ntp_gettime() returns code 0 (OK)
time de6eb184.e5ba3ca8 Wed, Apr 4 2018 4:05:56.897, (.897373194),
maximum error 325351 us, estimated error 1085 us, TAI offset 0
ntp_adjtime() returns code 0 (OK)
modes 0x0 (),
offset -244.122 us, frequency -1.885 ppm, interval 1 s,
maximum error 325351 us, estimated error 1085 us,
status 0x2001 (PLL,NANO),
time constant 10, precision 0.001 us, tolerance 496 ppm,
--
--
Michael van Elst
Internet: mlelstv%serpens.de@localhost
"A potential Snark may lurk in every tree."
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