Thanks, glad to see I'm not the only one with the issue. Did some more searching and it seems it only logs the sync that happens at daemon start up, but is supposed to resync at some compiled in interval. Check the most recent sync time with the times from stat /var/lib/systemd/clock
On my Debian 8.9 Beaglebone Green I changed /etc/systemd/timesyncd.conf to have a line: NTP=pool.ntp.org This is the server that I know is being used by the Lorex DVR device which is the most important wrt the time sync with my Beaglebone Green. I then did: sudo systemctl stop systemd-timesyncd sudo systemctl start systemd-timesyncd and sudo systemctl status systemd-timesyncd showed I was apparently now using the pool.ntp.org server. Using: stat /var/lib/systemd/clock Mine seems to be updating every 35 seconds, although apparently the interval will change as sync gets better/worse. After doing this about 45 minutes ago my Beaglebone is now within 1 second of the Lorex, where it was about 5 seconds off before. Is it possible that extra jitter in the time functions is caused by a fairly heavy and variable workload? tops shows load averages: 0.20 .010. 0.07 OTOH my BBW Debian 9.2 system, which has been up about a day longer than the BBG (did a test reboot yesterday) now seems well synced, but it is very lightly loaded basically just running my ssh session to make these tests. The systemd-timesyncd update interval seems to be about 34 minutes. So I'm not sure what is really going on here, but as long as the BBG and the Lorex stay synced to +/- 1 second I don't need to understand it :) On Friday, December 8, 2017 at 10:34:32 PM UTC-6, Graham wrote: > > I have been chasing something similar. > On Debian 8.8 and prior Jessie versions, systemd-timesyncd worked very > well and issued a lot of (level debug) messages that told you what was > going on, and the level of correction being applied. > When it is running the time would stay synced within 20 milliseconds or so. > > On Stretch, I have been unable to receive any of these update messages. > Normally every 30 minutes, after initial correction convergence. > rsyslog is correctly configured to capture them. > > All I see is a single syslog message at the time of initial sync, then > nothing. > > I am unable to convince myself that systemd-timesyncd is actually running, > even though > > systemctl status systemd-timesyncd.service > > says that it is. > > --- Graham > > == > > On Friday, December 8, 2017 at 9:39:21 PM UTC-6, [email protected] wrote: >> >> I've an IOT application distributed over multiple systems all on a local >> network and all synchronized with some flavor of ntp running. >> >> These all stay syncronized to within a second over long periods: >> Raspberry Pi2 >> Raspberry Pi3 >> Raspberry PiZero-W >> Ubuntu 16.04 desktop >> Commercial Lorex security DVR >> >> These two have drifted about three seconds slow already, although they >> seem well synced with each other: >> Beaglebone Green running Debian 8.9 (rebooted this morning) >> Beaglebone White running Debian 9.2 (booted yesterday morning) >> >> >> All the Raspberries are running Raspbian, verson 8 for the Pi2 and >> version 9 for the rest >> >> My initial assumption is somehow they are using different time servers >> that have a systematic error. Problem is I can't find where the >> systemd-timesync stores its servers to see if Beaglebones ntp server >> settings matches the others. >> >> The Lorex box would drift until I changed it sync interval from 6 hours >> to 1 hour. All the systems that now stay synced appear to be using >> pool.ntp.org, I can't seem to find where the Beaglbones store the >> server they use. >> >> Like with most things systemd I'm finding lots of misleading and >> confusing information that is generally not matching what I'm finding on my >> systems, but the Beaglebone solution may be as simple as it was for the >> Lorex device -- shorten the sync interval. But how do I find what the >> interval is and then how do I shorten it? >> >> This system has been running and evolving since 2015, and I've noticed >> the Beaglebones generally would be "off" + or - a few seconds from the >> beginning of development, but I'm just now getting to adding the feature >> that needs time sync accurate within one second. >> >> >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/c25c66eb-d669-43f1-9674-53e6361462d6%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
