I had hard time fixing an NTP bug that I came across.
The setup had hardware clock and software clock in sync.
We configured the NTP servers for the machine and in few minutes the system time would go around 7 hours back.
On doing: ntpq -p :
remote refid st t when poll reach delay offset jitter
=========================================================================
ntp-1****. .GPS. 1 u 28 64 3 49.992 2611013 2611013
ntp-2****. IP Address 2 u 51 64 3 570.113 2611038 2611039
Both the offset and jitters are high. And was not sure if one is caused by another and what might be issues if one of them is high and the other is not. And can i run into the same problems.
Well I tried a fresh machine, made the hardware clock back by 7 hours. Synced the system clock to the same time and then tried the same ntp servers. (( I could have only changed the system time)) I could see a great offset value and no jitter. In 5 minutes time the clock was synced to NTP.
If jitter is the problem, we need to find out why jitter might get high.
The setup had hardware clock and software clock in sync.
We configured the NTP servers for the machine and in few minutes the system time would go around 7 hours back.
On doing: ntpq -p :
remote refid st t when poll reach delay offset jitter
=========================================================================
ntp-1****. .GPS. 1 u 28 64 3 49.992 2611013 2611013
ntp-2****.
Both the offset and jitters are high. And was not sure if one is caused by another and what might be issues if one of them is high and the other is not. And can i run into the same problems.
Well I tried a fresh machine, made the hardware clock back by 7 hours. Synced the system clock to the same time and then tried the same ntp servers. (( I could have only changed the system time)) I could see a great offset value and no jitter. In 5 minutes time the clock was synced to NTP.
If jitter is the problem, we need to find out why jitter might get high.
There could be several issues why jitter is high:
1. I am still to know if jitter could be high because NTP servers are indicating different offset values.
2. It can be because the system tick is too low or too high.Pasky's Blog gives a good introspection of the same.
? Other reasons..
? https://groups.google.com/forum/?fromgroups#!topic/comp.protocols.time.ntp/cEZVWFi49Wg
? https://groups.google.com/forum/?fromgroups#!topic/comp.protocols.time.ntp/cEZVWFi49Wg
Related Info:
the log files are in /var/log/daemon.log
Ended in a condition: time correction of 26108 seconds exceeds sanity limit (1000); set clock manually to the correct UTC time
the log files are in /var/log/daemon.log
Ended in a condition: time correction of 26108 seconds exceeds sanity limit (1000); set clock manually to the correct UTC time
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