[ntp:questions] Frequency Error on Sun4v

Brian Utterback brian.utterback at sun.com
Fri Jun 20 13:30:18 UTC 2008

Hal Murray wrote:
> [drift > 500 ppm]
>> It's almost certainly a hardware problem.  Ntpd is telling you that the 
>> clock is gaining, or losing, more than about 43 seconds (500 parts per 
>> million) per day.  500 PPM is the maximum that ntpd can handle.
> It could easily be a software screwup.
> Unless you know it works on that particular type of hardware,
> I'd give software equal probability.

Do not even think about using NTP on a T1000, T2000, or T5120 until 
you have the latest firmware patch installed (nah-nah, wasn't hardware 
  OR software. Or maybe both?).  There is a bug in all three that 
causes the firmware to report an incorrect clock frequency to the 
kernel on boot up. Interestingly, the bug in the T1000 and T2000 is 
different from the bug in the T5120. See my blog post at 
http://blogs.sun.com/blu/entry/spread_spectrum_emi_and_the for an 
explanation of the T5120 issue.

Brian Utterback

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