Very Computer

by **A. Ian Vogelesan** » Mon, 28 Oct 1996 03:00:00

Kernel 2.0.10 (but has been occurring for a _long_ time ...)
Running NTP, with time being set directly from a WWV clock receiver.

Time continuously slews; every few minutes NTP makes a
step adjustment to get it back into sync. Unlikely to
be hardware, because it happens exactly the same on
a P90 and a P6-200 SMP.

Ideas?

by **Bob Hau** » Tue, 29 Oct 1996 04:00:00

Quote:> Kernel 2.0.10 (but has been occurring for a _long_ time ...)
> Running NTP, with time being set directly from a WWV clock receiver.

> Time continuously slews; every few minutes NTP makes a
> step adjustment to get it back into sync. Unlikely to
> be hardware, because it happens exactly the same on
> a P90 and a P6-200 SMP.

Use "tickadj" to tweak the kernel time increment. I had this exact
problem (without a radio clock). Basically, the clock oscillator
on the motherboard was too far off for ntp to discipline it.

I put "tickadj 9997" in the boot script on that machine and it works
fine now. I actually have several PC's here where the motherboard
clock is off by more than the allowed 300 ppm. Newer motherboards
actually seem to be worse than older ones in this respect.

This was with a 1.2.13 kernel with the pll patch. Don't know if
anything changed WRT timekeeping in 2.0, but if it did that could
be causing you grief as well.

---

Wasatch Communications Group http://www.wasatch.com

Very Computer

NTP time slews continuously - why?

NTP time slews continuously - why?

NTP time slews continuously - why?