[ntp:questions] NTP.log interpretation

GregL greg.leibfried at gmail.com
Fri Apr 18 15:38:10 UTC 2014


> On Fri, Apr 18, 2014 at 09:01:09AM -0500, GregL wrote:
> > >   What you should do is to add more servers to the config.
> >
> > What about the idea of going to only one entry, but that entry is served
> by
> > a DNS load balancer to choose one of two internal time servers to check.
> >  Each of those, is configured to point at a pool of time servers (4
> each).
>
> Well, that will prevent the client from detecting it's getting wrong
> time. Is that what you want?
>
>
I'm wrestling with that very question.  With 100+ systems, we have a far
greater problem if some systems are *off* and others are not.

>From the log it seems that at least one server is completely wrong,
> the offset between the two servers is around 3 seconds! I'd suggest to
> fix that first.
>
>
Yes, clearly the root of the most recent problem was a faulty configuration
that allowed our internal time servers to grow to nearly 50 seconds apart
at some point....and that wreaked havoc in many many areas.

That is fixed, and our two internal time servers *should* be correct.

Now, I'm just planning on making changes to the ntp.conf, like adding the
"-x" parameter.  I'm hoping that that will prevent huge time resets
backwards in time...should that ever be even possible again.

But, was the "sychronization lost" message *because* ntp saw the time
difference so great on peer servers...and chose one to synch to...resulting
in the time reset message?


More information about the questions mailing list