David Lord wrote:
Miguel Gonçalves wrote:
Hi all!
I am having a problem with a Dell server that has a Garmin 18 LVC
attached.
It's a FreeBSD 7.4 machine with the Garmin 18 LVC connected to a
serial port
(PPS on DCD pin). The kernel has been compiled with the line "OPTIONS
PPS_SYNC". NTP is 4.2.4p5.
Here's the ntp.conf file:
server 127.127.20.0 mode 2 iburst prefer
fudge 127.127.20.0 flag3 1
server ntp-p1.obspm.fr iburst
server ptbtime1.ptb.de iburst
server ntp.inrim.it iburst
server ntp1.oma.be iburst
server canon.inria.fr iburst
server time.fu-berlin.de iburst
server chronos.csr.net iburst
server ntp1.nl.uu.net iburst
statsdir /var/log/ntp/
filegen clockstats file clockstats type day enable
filegen peerstats file peerstats type day enable
filegen loopstats file loopstats type day enable
statistics clockstats peerstats loopstats
logfile /var/log/ntp/messages
restrict default kod nomodify notrap nopeer
restrict 127.0.0.1
I've disabled ACPI in /boot/loader.conf (hint.acpi.0.disabled=1) but
did not
disable serial FIFO.
I am getting very high offsets and jitter for this reference clock:
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_NMEA(0) .GPS. 0 l 40 64 377 0.000 -0.031
0.043
+ntp-p1.obspm.fr .TS-3. 1 u 50 64 377 54.154 1.611
1.843
-ptbtime1.ptb.de .DCFa. 1 u 119 64 376 70.069 -2.174
1.283
-ntp.ien.it .CTD. 1 u 35 64 377 65.682 2.037
6.667
-ntp1.oma.be .PPS. 1 u 26 64 377 61.911 2.280
3.673
+canon.inria.fr .GPSi. 1 u 30 64 377 54.626 1.442
1.700
-time.fu-berlin. .PPS. 1 u 32 64 377 73.342 -0.292
3.136
-chronos.csr.net .GPS. 1 u 32 64 377 85.049 -3.656
5.096
-ntp1.nl.uu.net .PPS. 1 u 2 64 377 67.085 3.435
3.888
tick# ntpdc -c kerninfo
pll offset: -7.886e-06 s
pll frequency: -6.729 ppm
maximum error: 0.030005 s
estimated error: 6e-06 s
status: 2107 pll ppsfreq ppstime ppssignal nano
pll time constant: 6
precision: 1e-09 s
frequency tolerance: 496 ppm
pps frequency: -6.729 ppm
pps stability: 0.312 ppm
pps jitter: 4.03e-07 s
calibration interval: 256 s
calibration cycles: 152
jitter exceeded: 1029
stability exceeded: 0
calibration errors: 3
It seems the internal clock of the machine is going nuts (small
snippet of
loopstats file):
55822 70649.300 0.000037529 -6.306 0.000000816 0.139388 6
55822 70714.307 0.000004089 -6.175 0.000001464 0.138376 6
55822 70779.307 -0.000029839 -6.175 0.000013699 0.129439 6
55822 70845.306 -0.000058655 -6.175 0.000000562 0.121079 6
55822 70909.305 -0.000078382 -6.175 0.000000570 0.113259 6
55822 70972.305 -0.000061801 -6.729 0.000001320 0.222533 6
55822 71035.304 -0.000041884 -6.729 0.000000778 0.208161 6
55822 71100.304 -0.000023847 -6.729 0.000000629 0.194717 6
55822 71166.303 -0.000003148 -6.595 0.000001515 0.188165 6
55822 71232.302 0.000006531 -6.595 0.000004666 0.176012 6
NetBSD-5, ntpd 4.2.6p3
My time sync has blipped twice each evening at times when
system load is high during log creation/rotation. Mostly
I don't notice. Currently I'm using a Sure-Electronics
but my Garmin 18x-LVC was the same. Blips are from < 15u
up to over 40u.
peerstats.20110918
ident mean rms max delay dist disp
127.127.20.2 -64.698 15.422 60.828 0.000 2.525 1.742
127.127.22.2 0.000 0.000 0.048 0.000 0.928 0.920
^
Sorry my eyesight is bad. RMS should have been 0.008
and averaged over last 20 days is 0.0056 although packages
on that system have been upgraded and system rebooted
during that period.
David
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