Re: [chrony-dev] Let the kernel write the sys clock to RTC

[Bill Unruh <unruh@xxxxxxxxxxxxxx>]

On Thu, 13 May 2010, Piotr Grudzinski wrote:

> Hi All,
>
> I would like to use chronyd on a small uClinux based system running unattended 24/7.
> The kernel can write the system time to the RTC every 11 minute if the clock status ever
> becomes SYNC; but it seems to be intentionally kept UNSYNC by chronyd.
> Reading some latest posts, there seems to be some agreement that this would be a useful feature.
> Are there any plans to have it implemented?

This is a terrible feature. 
chrony keeps track of the rtc and estimates teh drift rate of the rtc and the
offset. The 11 min procedure destroys that utterly. It makes it completely
impossible to calculate the drift of the rtc, which means you cannot
compensate for it when you switch off and on later. Remember that the rtc is
NEVER used while the system is running. If you want to use the newest hwclock
it can also estimate the drift rate but that ability is destroyed if you use
the 11 min mode. There is absolutely no situation where the 11 min mode is
useful.
Curnow purposely disabled the 11 min mode for all the above reasons. Why would
you want to have it?

> Best Regards,
> Piotr

--
William G. Unruh   |  Canadian Institute for|     Tel: +1(604)822-3273
Physics&Astronomy  |     Advanced Research  |     Fax: +1(604)822-5324
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