<div dir="ltr">If we make this change, framing it as "it's how chronyd has been doing it for the past N years" makes it a much easier sell.<div><br></div><div>Especially if we can make the file format the same.</div><div><br></div><div>What principled objections would the hardcore time nerds have? We do have to keep their needs firmly in mind.</div><div><br></div><div>..m</div></div><br><div class="gmail_quote"><div dir="ltr">On Mon, Aug 1, 2016 at 7:40 PM Gary E. Miller <<a href="mailto:gem@rellim.com">gem@rellim.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Yo All!<br>
<br>
Eric asked me to write up why I thought the chrony drift file handling<br>
is better than NTPsec's handling.<br>
<br>
1. On startup chronyd checks the time stamp on the drift file.<br>
if the timestamp > sysclock, the sysclock is set to the timestamp<br>
<br>
This is a nice sanity check on the system clock.<br>
<br>
2. ntpd stores the frequency ppm offset in the driftfile.<br>
chronyd stores the frequency ppm offset and the 'skew' (estimated accuracy<br>
of the existing frequency value).<br>
<br>
Knowing the 'skew' at startup allows chrony to better reject bad<br>
reclock input.<br>
<br>
I can see that saving the 'skew' is a nice touch, but I suspect much the<br>
good chronyd startup behavior is explained elsewhere.<br>
<br>
In a related topic, it would be nice (maybe an option) for ntpd to hold<br>
off logging the initial aweful data until after the -g option has<br>
set the system clock. And a bit longer, so the wonky startup data is<br>
masked.<br>
<br>
RGDS<br>
GARY<br>
---------------------------------------------------------------------------<br>
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703<br>
<a href="mailto:gem@rellim.com" target="_blank">gem@rellim.com</a> Tel:+1 541 382 8588<br>
_______________________________________________<br>
devel mailing list<br>
<a href="mailto:devel@ntpsec.org" target="_blank">devel@ntpsec.org</a><br>
<a href="http://lists.ntpsec.org/mailman/listinfo/devel" rel="noreferrer" target="_blank">http://lists.ntpsec.org/mailman/listinfo/devel</a></blockquote></div>