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Re: Minor NTP question ....



On 04/20/15 00:22, Michael van Elst wrote:
wam%hiwaay.net@localhost ("William A. Mahaffey III") writes:

[wam@fly, ~/Suspect, 4:58:50pm] 334 % ntpq -pn
      remote           refid      st t when poll reach   delay offset
jitter
==============================================================================
-216.180.99.1    128.59.59.177    3 u  947 1024  377    0.340 10.937   0.434
-216.180.122.1   198.82.247.51    3 u  358 1024  377    2.706 12.187   1.078
+208.75.88.4     69.36.224.15     2 u  384 1024  377   79.207 -5.931   0.584
+98.143.24.53    64.250.229.100   2 u  472 1024  377   47.575 6.415   0.006
*204.2.134.163   187.253.153.32   2 u  969 1024  377   77.611 2.938   0.155
[wam@fly, ~/Suspect, 4:58:53pm] 335 % cat /var/lib/ntp/drift
-28.010
[wam@fly, ~/Suspect, DING!] 336 %
& we have a winner !!!! That -28-ish isn't so bad, but with so much
difference between its 3 external sources,
Hmm,

the offset values are in milliseconds, your external sources are pretty
close.

I was refering to the drift value, it says that your system clock
has a deviation of 28ppm (about 2.4 seconds per day). But that's
an average, the real deviation could be different, in particular,
when the system is busy or if it is booting.
The RPI has no clock chip, every reboot resets the clock to the
timestamp of the root filesystem.

Ahhhh, I wasn't aware of that (offsets in usec.), that helps. I do have a DS3231 clock chip on my RPiB+, although someone else mentioned that it is not (yet) supported. Does NetBSD-7 write system time to whatever saves time on the mbd on poweroff ? It seems that when I have a power burp that gets the RPi, it comes back up w/ pretty good time right away, even w/ no internet available ....

--

	William A. Mahaffey III

 ----------------------------------------------------------------------

	"The M1 Garand is without doubt the finest implement of war
	 ever devised by man."
                           -- Gen. George S. Patton Jr.



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