[mdlug] 2 very different gigabyte motherboards not keeping good time

[Dan Pritts]

On Apr 16, 2014, at 9:36 AM, Dan Pritts <danno at dogcheese.net> wrote:

> Thanks for taking the time to reply.  
> 
> All this said, I started NTP again on monday, and the system has kept proper time.  
> 
> I suppose it’s possible that somehow I had an out-of-sync clock that wasn’t set 
> properly at boot time, and ntp hadn’t been able to catch up yet.  But, ntp starts 
> up with the -g option so that seems unlikely too.  Maybe the network didn’t 
> come up properly at first, or something.  
> 
> Piss me off.

Nope, that wasn’t the problem.  It started to drift again.

I’ve got more data, and a theory.

1) i’ve watched the jitter numbers and they are high.  I suspect this is due to a combination of random 
comcast crappiness, and the fact that I have lots of network activity on this system.

I suspect this had something to do with NTP’s recalcitrance to set the clock.  

2) I had decreased the polling frequency of a stratum 1 server that I poll at my former employer, 
just to avoid being too needy.  

I set it to minpoll 8, which is 256 (2^8) seconds.  i’d apparently done that with the pool.ntp.org servers too.
However, i had a stratum 2 at umich with the defaults, and I’m pretty sure that in the past i’d tried multiple
servers with defaults and some with higher minpoll values.  

Anyway,  I removed all the minpoll values, which seems to have helped a lot.  The clock is still drifting pretty 
badly, but NTP is keeping it in line.  

danno