[ntp:questions] Very large offset and jitter values after reboot
nb at komeda-berlin.de
Sun Aug 24 22:53:27 UTC 2008
Richard B. Gilbert schrieb:
> Nicola Berndt wrote:
>> I have now successfully set up my machine to use a usb-gpd-mouse to set
>> the time. Strangely every time I reboot I get results like this, wich
>> settle down after a (not so short) while:
>> remote refid st t when poll reach delay offset
>> GPS_NMEA(0) .GPS. 0 l 9 64 37 0.000 -580.75
>> The problem is, that this takes rather long and the computer's job
>> actually is, to provide exact time outdoors right after booting..
>> I already tried what would happen if I did a 'hwclock --systohc' once
>> things are settled, but with no luck. My driftfile btw. says -35.666 -
>> looks good to me - and I am very worried about the huge jitter...
>> Any ideas for me, anyone?
>> Thx and regards,
>> ../nico berndt
> 1. Don't reboot! My Windows, Linux, Solaris, and OpenVMS systems will
> all run until the power goes off for longer than the run time of my UPS.
> 2. Start ntpd with the "-g" switch. The -g switch tells it to get and
> set the correct time. Following startup, ntpd will discipline the clock
> in the usual way. It may take a relatively long time, around thirty
> minutes, to settle into really tight synchronization.
1, As I wrote already, the device has to work outdoors, where there is
no unlimited power-source, so I have to reboot. Also I think, a computer
that cannorttake a reboot has a problem wich needs to be adressed. Just
my opinion, though..
2, I forgot to mention that I already do so, still takes too long to
settle. I also don't understand what is taking so long, since - jitter
or not - the nmea time is precise enough to just quickly set the time at
startup and then let things go their way. Can someone explain that to me?
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