Re: [chrony-users] Intermittent network access even at boot

[Ed W <lists@xxxxxxxxxxxxxx>]

Hi

I am working on a line of Linux products that have an RTC with no battery, so it returns to Jan 1970 every time it is powered off/on.  After attempting to use openntpd for a while, we see that Chrony is a much better fit.  Our device may run without network for long times, even at boot time, and so we need some way for the device to start up, and get time later.

Clearly you can't get the exact time without an RTC, but if you look at the gentoo startup script swclock you will see that it uses some known file on disk as a time reference source and sets the time to be this on boot.  This will clearly always be "behind" the last known time, but it does have the benefit of being monotonic (with a bit of thought) and this may be helpful for certain scenarios

I should think you wouldn't copy the script exactly so much as the idea...
 

Hanging within the startup scripts is not acceptable because we have other daemons that also need to be started, whether or not we have a network.

I believe that it works fine for you out of the box - but a quick check should be very easy?
 

The README indicates that if DNS is not available at startup, it will not be consulted later.  Is this still the case?

I think some changes have been made here to make this possible, but I'm not so sure - you will need a recent version and some testing I guess

 

Good luck

Ed W