[ntp:questions] ntpdate works, but ntpd doesn't (reach = 0)

Unruh unruh-spam at physics.ubc.ca
Fri Feb 13 16:27:25 UTC 2009


Martin Burnicki <martin.burnicki at meinberg.de> writes:

>Unruh wrote:
>> "Richard B. Gilbert" <rgilbert88 at comcast.net> writes:
>[...]
>>>I'd be very cautious about using a drift file that was much more than
>>>one hour old.  If the environment (temperature) has remained constant
>>>you are probably okay but the greater the length of time you are down
>>>the greater the uncertainty of the time you will start up with.
>> 
>> On Linux these days, even a drift file that is 10 sec old is useless,
>> since the system clock drift rate changes by up to 50PPM over a reboot.

>... which would not even be noticed if ntpd would initially apply
>corrections faster.

Agreed. chrony for example compensates within less than 15 min to bring the
system under control and time errors of 10s of microseconds. 


>Martin
>-- 
>Martin Burnicki

>Meinberg Funkuhren
>Bad Pyrmont
>Germany




More information about the questions mailing list