[ntp:questions] Setting up a NTP Time Server

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Tue Apr 8 06:39:20 UTC 2008


>Can someone point me to a good document that
>shows how to setup a Time Server?  I have an
>isolated network that cannot get to the Internet
>to sync time.  I have Solaris 8,9,10 and Red Hat Linux
>Advanced Server 4 servers as potential time server
>candidates.

I don't know of any document that covers this case.
It does come up occasionally.  There might be some
ideas in the newsgroup archives.

I think your top level decision is do you want to setup
a refclock or do you want to coast between manual corrections.

For under $100 you can rig up a GPS clock.  The Garmin
GPS 18 LVC is usual suggestion.  That will give you good
time.  I don't know anything about Solaris.  Linux needs
a serious patch to get PPS support.  Without PPS support,
your time won't be "good".  It will be much better than
coasting without any refclocks.

If you don't use a refclock, you can set things up
to distribute the local system clock.
  http://www.cis.udel.edu/~mills/ntp/html/drivers/driver1.html

It will drift between (manual) corrections.  You can
minimize that drift by calibrating your clock drift
and putting the right value in the drift file.
If your temperature and workload are reasonably stable,
I'd expect you can get close to a second per week.


A few odds and ends....

The documentation for ntp is web pages, not man pages.

There are generally 2 versions of ntp available: stable and dev.
(There are also older version floating around too.)
The dev version has new features, like the orphan mode.  Maybe
it has new bugs too.  If you find web page via google, you
don't know which version it is refering to.  If you can, use
the documentation that comes with the version of ntp you are running.

I'd suggest a pass through all of the web pages.  Skim the stuff
that doesn't look interesting.  Go back and read the important stuff
more carefully.

Linux 2.6 kernels have a bug in the tsc calibration code.  That will
confuse things if you try to manually calibrate the drift.  (I'll say
more if you get that far.)


-- 
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