Patrick Nolan wrote: > On 2007-10-19, Richard B. Gilbert <[EMAIL PROTECTED]> wrote: > >>Some Linux systems have known problems with losing timer interrupts! >>During periods of heavy I/O load disk drivers may mask or disable >>interrupts for a little too long a time. . . . Some Windows systems >>have also been known to exhibit similar behavior. > > > I would like to know more about this. How can I monitor the interrupts? > > After my original post, I remembered that this machine has a unique > feature. I compiled a new kernel to add the Reiser file system. > I don't think I changed anything else, but I don't have any previous > experience with custom kernels. > > >>What's the value stored in your drift file? > > > Currently it's 74.080. This morning it started out around 30. > > >>DON'T use burst! The burst keyword was intended for situations where >>ntpd has to make a phone call to NIST (or similar service) to get the >>time. It is NOT suitable for general use over the internet. > > > Without burst, it just drifts freely. The size of the drift is even > worse than I thought. With burst, here are some lines from the log > file: > > Oct 19 13:37:23 client ntpd[12595]: time reset +13.151972 s > Oct 19 13:55:58 client ntpd[12595]: time reset +8.779090 s > Oct 19 14:08:09 client ntpd[12595]: time reset +8.712040 s > Oct 19 14:28:21 client ntpd[12595]: time reset +11.494533 s > Oct 19 14:44:53 client ntpd[12595]: time reset +9.450835 s > > If I ever get this situation under control I'll turn off burst. > > >>Iburst is good. It gets you a fast startup and then lets your system >>poll the server at normal intervals. >> >>Check the value of a Kernel variable called "HERTZ". Some Linux systems >>set it to 1000 which is not good for NTP. If yours is set to 1000 (or >>250) try changing it to 100. > > > More ignorance on my part. Where would I look for this? I searched > the kernel source code and didn't find it. > <snip>
Sorry, I've read about HERTZ but I'm not a Linux expert, have never experienced the problem, or actually done the fix. _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
