[MacTUG] a drifting network time

Tue Apr 24 16:34:27 EDT 2012

So sending this through Apple Remote Desktop (as root user) changed my time server to what Dawn suggested:
systemsetup -setnetworktimeserver ntp1.uwaterloo.ca
And running this confirmed the change had been made:
systemsetup -getnetworktimeserver

But here is the weird part:
I can put whatever I want in the time server address (even garbage) and it purports to work (I am guessing if the URL doesn't have a time service it just defaults to time.apple.com)

For example I do the following

  1.  Turn on Set date and time automatically, and enter a bogus url (like this_is_no_server.company.org) and hit the return to lock the url in
  2.  I then turn it off and manually change the time to something wrong — you will notice that the url entered in the previous step is still remembered
  3.  I then turn it back on and it 'magically' restores the time to the correct date.

Crazy. So you can put in a time server url that is phoney-balloney

Any insights would be welcome but not required, haha.

I think part of my future rebuild strategy will be to include a forcing of all the clients to update their time before I rebuild them.

don

------------------------------------
Donald Duff-McCracken
Technical Services Manager
Mapping, Analysis & Design
Faculty of Environment
University of Waterloo
(519) 888-4567 x32151
http://www.environment.uwaterloo.ca/computing/people/don.html
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To request help from MAD please use Request Tracker. For info see:
http://environment.uwaterloo.ca/computing/faculty_staff/

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On 12-04-24 3:38 PM, "Donald Duff-McCracken" <dsmccrac at uwaterloo.ca<mailto:dsmccrac at uwaterloo.ca>> wrote:

Thanks Gang.

Dawn, I will try the servers you suggest.

don
------------------------------------
Donald Duff-McCracken
Technical Services Manager
Mapping, Analysis & Design
Faculty of Environment
University of Waterloo
(519) 888-4567 x32151
http://www.environment.uwaterloo.ca/computing/people/don.html
------------
To request help from MAD please us "Request Tracker". For info see: http://www.fes.uwaterloo.ca/computing/faculty_staff/
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This email communication is intended as a private communication for the sole use of the primary addressee and those individuals listed for copies in the original message. The information contained in this email is private and confidential and If you are not an intended recipient you are hereby notified that copying, forwarding or other dissemination or distribution of this communication by any means is prohibited.  If you are not specifically authorized to receive this email and if you believe that you received it in error please notify the original sender immediately.
________________________________________
From: mactug-bounces at lists.uwaterloo.ca<mailto:mactug-bounces at lists.uwaterloo.ca> [mactug-bounces at lists.uwaterloo.ca<mailto:mactug-bounces at lists.uwaterloo.ca>] on behalf of Keith McGowan [kmcgowan at uwaterloo.ca<mailto:kmcgowan at uwaterloo.ca>]
Sent: Tuesday, April 24, 2012 11:54 AM
To: Dawn Keenan; mactug at lists.uwaterloo.ca<mailto:mactug at lists.uwaterloo.ca>
Subject: Re: [MacTUG] a drifting network time

I agree with Dawn that the time servers should be set to the local ntp1/ntp2 since that is the source of the time for Kerberos in the AD's.

The following article describes what may be happening...

http://support.apple.com/kb/TA24116?viewlocale=en_US

...which mentions...

"Some Mac OS X computers will lose time synchronization even when the "Set date & time automatically" option is selected in the Date & Time preference pane. To temporarily resolve the issue, simply deselect and then reselect that checkbox.

To permanently resolve the issue, you can modify the default values in the time synchronization configuration file. The defaults require several hours of constant access to the time server in order to establish synchronization. If the initial sync gets interrupted (by the computer going to sleep, for example), the subsequent synchronization will not take place, causing the computer to eventually drift from the correct time."

...Keith

--
Keith McGowan - Arts Computing Office - University of Waterloo
kmcgowan at uwaterloo.ca<mailto:kmcgowan at uwaterloo.ca> - 519-888-4567 x33158

-----Original Message-----
From: mactug-bounces at lists.uwaterloo.ca<mailto:mactug-bounces at lists.uwaterloo.ca> [mailto:mactug-bounces at lists.uwaterloo.ca] On Behalf Of Dawn Keenan
Sent: April-24-12 11:10 AM
To: mactug at lists.uwaterloo.ca<mailto:mactug at lists.uwaterloo.ca>
Subject: Re: [MacTUG] a drifting network time

I'd recommend ntp1.uwaterloo.ca or ntp2.uwaterloo.ca. While they may be the same hardware as the campus name servers, IST could theoretically move the service anywhere.

When I was in CS, we had a local NTP service running on one of our servers and used it as the time source for both AD and the Macs.

Dawn

On 12-04-24 10:55 AM, Donald Duff-McCracken wrote:
Does anyone else have lazy macs that do not update their network time
frequently enough and have their time drift by a few minutes?

It happens to me fairly frequently, and every now and then a mac
drifts in its time by more than 5 minutes so that it cannot synch with
active directory.

I have a question and then a semi-solution:

QUESTION: What time server are you guys using? I am using
ns1.uwaterloo.ca - I use this instead of time.apple.ca as I really do
not care if I have the 'right' time but just want a time that is right
from the perspective of the servers on campus. I figure if I am using
a campus time server if time drifts on campus I can still synch with AD.
Bernie suggested I try synching with Nexus, and it seems that
nexus.uwaterloo.ca is serving up time and it seems to work. Anyhow,
what time servers are people are folks using? (I am most interested in
macs that are hooking up to AD, not personal machines which likely are
hooked up to time.apple.com)

My Semi-Solution:
Send this command out from good old Apple Remote Desktop (as root) to
all my machines:

     /ntpdate -u time.apple.com/

/
/
It updates the time. I ran this just now and a lot of my macs were off
by hundreds of seconds!

Don
------------------------------------
Donald Duff-McCracken
Technical Services Manager
Mapping, Analysis & Design
Faculty of Environment
University of Waterloo
(519) 888-4567 x32151
http://www.environment.uwaterloo.ca/computing/people/don.html
------------
To request help from MAD please use Request Tracker. For info see:
http://environment.uwaterloo.ca/computing/faculty_staff/

------------
This email communication is intended as a private communication for
the sole use of the primary addressee and those individuals listed for
copies in the original message. The information contained in this
email is private and confidential and If you are not an intended
recipient you are hereby notified that copying, forwarding or other
dissemination or distribution of this communication by any means is
prohibited. If you are not specifically authorized to receive this
email and if you believe that you received it in error please notify
the original sender immediately.

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--
Dawn Keenan
Manager, Arts Computing Office, University of Waterloo dkeenan at uwaterloo.ca<mailto:dkeenan at uwaterloo.ca>
519-888-4567 x32157
PAS 2033
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