Re: [chrony-users] New with 1.30: stuck after resume from suspend

[ Thread Index | Date Index | More chrony.tuxfamily.org/chrony-users Archives ]


On 07/03/14 14:06, Miroslav Lichvar wrote:
> This is probably related to the new detection of forward time jumps,
> which was mainly intended to handle system suspends. When chronyd

I read that in the release notes and figured as much. :-)

> When this happens, in the log you should see a "forward time jump was
> detected" message, immediately followed by "no reachable sources" and
> then in about 2 minimum polling intervals (assuming the suspend was
> longer than the polling interval used before suspend) a new source
> should be selected.

Indeed - from this morning's wakeup, after sleeping overnight:

Jul  3 09:18:39 hho chronyd[28177]: Forward time jump detected!
Jul  3 09:18:39 hho chronyd[28177]: Can't synchronise: no reachable sources
Jul  3 09:19:19 hho chronyd[28177]: Selected source 192.168.100.222

I don't remember how long I waited for it to restart polling before kicking it, but I'm sure it was >> 2*minpoll.

And just as I wanted to send this mail I figured I re-check on a second system (workstation, identically configured but newer/better HW), and what do you know? It woke up and started syncing right away:

Jul  3 14:33:05 ragnarok chronyd[2529]: Forward time jump detected!
Jul  3 14:33:05 ragnarok chronyd[2529]: Can't synchronise: no reachable sources
Jul  3 14:33:43 ragnarok chronyd[2529]: Selected source 192.168.100.222

...and it's runnig fine now. That system ran with a shorter polling interval since I suspended briefly after reboot, so it was still at minpoll.

> Interesting. I suspect the scheduled timeout got lost somehow.

Apparently not always. The laptop where this happened is pretty old though (Thinkpad T60 from ~2007) with a pretty dodgy clock, so maybe it's a race/timing condition somewhere.

I will verify the behaviour again when polling has reached a higher value.

> How is your chronyd configured? Do you set the online/offline status
> from chronyc?

No, laptop/workstation start chrony at boot and continously sync to an always-on inhouse chronyd server ("ntp") for reference, with a very minimal config:

server ntp iburst minpoll 4 maxpoll 8
initstepslew 1 ntp

...plus various other unrelated settings like keyfile, driftfile etc. Nothing fancy.

Other than this it's working fine, so no drama. For now I can add a post-wakeup script to kick it into gear with a few bursts. If you have any ideas I can gladly try patches/build from git if that would help.

thanks!
Holger

-- 
To unsubscribe email chrony-users-request@xxxxxxxxxxxxxxxxxxxx 
with "unsubscribe" in the subject.
For help email chrony-users-request@xxxxxxxxxxxxxxxxxxxx 
with "help" in the subject.
Trouble?  Email listmaster@xxxxxxxxxxxxxxxxxxxx.


Mail converted by MHonArc 2.6.19+ http://listengine.tuxfamily.org/