[ntp:questions] Problem with xntp after reinstall on openSUSE 10.3

Martin Burnicki martin.burnicki at meinberg.de
Tue Oct 16 07:56:14 UTC 2007


Marc,

first, I've also just upgraded a x86_64 machine to openSUSE 10.3, and see no
problems using the ntpd version with the distribution.

Marc Muehlfeld wrote:
> Richard B. Gilbert wrote:
>> My first guess would be that your local clock is off by more than 500
>> Parts Per Million (PPM).  500 PPM is the maximum frequency correction
>> that ntpd can make.
> 
> The PPM of current system accoring /var/log/messages: 5.706
> The old logfile showed: 161.758
> 
> 
> 
>> If you have a drift file, check the value stored in it.  Most machines
>> will have an absolute value less than 50.
> 
> The drift file of the new system consists: 6.194

This seems to indicate that the new kernel implements the system clock based
on a different timer API than the old kernel. That new timer API may not
support the particular chipset on your mainboard correctly.

As a test, you might stop ntpd, then set the system time manually running 

date -u; ntpdate ptbtime1.ptb.de

Then let the system time freewheeling, and run 

date -u; ntpdate -q ptbtime1.ptb.de

in some intervals. The latter command use "-q" to query only. It does not
set your system time, but reports the difference between the remote NTP
server and your system clock. Please report whether the difference is
growing slow or fast.

BTW, while using the pool servers as you have done is generally the
preferable way to run ntpd, for this particular test you should use a
dedicated server like one of the PTB servers in order to yield more
comparable results. 


Martin
-- 
Martin Burnicki

Meinberg Funkuhren
Bad Pyrmont
Germany




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