On 8/21/2013 23:57, David Woolley wrote:
On 21/08/13 21:24, A C wrote:
So the idea isn't that ntpd should figure out on its own without user
intervention. Instead there would be some kind of
configuration/fudge/tinker options available so that the user can supply
baseline information that can help ntpd identify a rogue source versus
normal system behaviors.
Actually, one of the main complaints about ntpd is that it favours the
theory that the source is the problem, when the crystal temperature is
the real problem. (The exception to this is people who manually yank
the local clock and then complain that ntpd doesn't immediately reset it.)
In most cases of steady drift or cyclical drift that may be true and I
certainly do see temperature effects on my system over the course of a
day. However in this particular case I can pretty much guarantee that
it's the source that caused the problem. I certainly didn't have a
temperature swing large enough to change the clock rate from -76 to -34
PPM in 16 seconds and then have it go back to -76 after 128 seconds (8 *
16) especially considering I was sitting in the room at the time it
happened staring at a thermometer that looks at the internal temperature
of the machine. The nominal swing caused by temperature on my system is
about 2-3 PPM (-76 to -73 or so) for an internal temperature swing of
about 10 degrees Fahrenheit.
_______________________________________________
questions mailing list
[email protected]
http://lists.ntp.org/listinfo/questions
