[ntp:questions] System time ramps forcing step correction?

AGC agcarver+netbsd at acarver.net
Sun Sep 9 22:05:19 UTC 2012


Has anyone seen a system with GPS/PPS have its system time ramp/slew 
ahead by over a second requiring a step correction?

My system has done it a few times now but it occurs randomly.  Nothing 
seems to be running at that point to bog the system down, but it 
steadily ramps up and then forces a step.  After the step correction it 
runs fine again without restarting anything.

The main log and peers log are included below for the relevant period. 
Everything is otherwise in working order.  I had offsets on the PPS 
signal of less than 50 us for days on end and then over several polling 
periods it suddenly slides up.  After the reset and settling time it 
once again shows 50 us or better offsets.

Sep  9 14:43:48 ntpd[15927]: 0.0.0.0 0113 03 spike_detect +0.199468 s
Sep  9 14:44:36 ntpd[15927]: SHM(0) 961a 8a sys_peer
Sep  9 14:48:36 ntpd[15927]: 0.0.0.0 041c 0c clock_step +1.637940 s
Sep  9 14:48:37 ntpd[15927]: 0.0.0.0 0415 05 clock_sync
Sep  9 14:48:38 ntpd[15927]: 0.0.0.0 c418 08 no_sys_peer
Sep  9 14:48:39 ntpd[15927]: 130.207.165.28 8074 84 reachable
Sep  9 14:48:41 ntpd[15927]: 64.73.32.134 8014 84 reachable
Sep  9 14:48:46 ntpd[15927]: 199.195.157.129 8014 84 reachable
Sep  9 14:48:47 ntpd[15927]: 131.144.4.10 8014 84 reachable
Sep  9 14:48:48 ntpd[15927]: 173.244.211.10 8014 84 reachable
Sep  9 14:48:54 ntpd[15927]: SHM(0) 8024 84 reachable
Sep  9 14:48:55 ntpd[15927]: SHM(0) 903a 8a sys_peer
Sep  9 14:48:55 ntpd[15927]: PPS(0) 80f4 84 reachable


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