SUMMARY: Sparcstation clocks

From: Leon Howorth (leonh%hhb@Princeton.EDU)
Date: Mon Jan 06 1992 - 14:16:03 CST


Thanks for all the responses to my original query:

> I have a number of sparcstations, some of which have clocks that
> are drifting by as much as 1 to 2 minutes per week. Anyone else
> experienced this problem and know the cause, fix, etc?

It appears that this is not unusual behavior for these machines. The
most often suggested workaround consists of syncing the workstations to
one or more local machines and syncing the "master(s)" to an accurate
outside source.

(The following suggested by a number of people):
------------------------------------------------
        Sync all the systems in question to a central local machine. If
nothing further is done to sync the time on the local source to some
accurate outside source then at least you'll be consistent in-house.
This can be done by putting rdate (8C) in a cron job on the workstations,
using a machine such as an NIS master or slave server as the source.

(Also suggested by Michael S. Maiten <princeton!Energetic.COM!msm>:
------------------------------------------------
I run a nightly script that adjusts the clocks on all the nodes
to within one minute (you can do better, this was adaquate for us).
The script uses the the -a option of date (uses adjtime(2)) to slowly
adjust the time without a jump. After this was installed, the time
sync problems dissappeared (at two sites where this was installed).

As far as syncing to an outside source:
------------------------------------------------

(Suggested by Ric ric@cs.arizona.edu <Ric Anderson>):

Yeah, ours drift like crazy. We stopped it with ntp (network time
protocol) so they all follow a chosen master, which synchs itself
with an external machine that tracks WWV.
ntp was obtained by ftp from trantor.umd.edu.

(Suggested by Pete Hartman pwh@bradley.bradley.edu):

"NTP" is Network Time Protocol and allows you to connect to a site
somewhere that has its time regulated by a device that reads the
shortwave WWV and keeps in good time all the time.

(Suggested by Brett Chapman sol.med.ge.com!blc):

The second method is to use ntp - Network Time Protocol. Using ntp
you can sync time to several sources, including some of which are on the
Internet. The advantage to ntp is that is calculates the time delay between
the time host and the target system. This keeps the time very closely in sync
with the time host. ntp is used more for larger networks and places where
systems must be within fractions of a second time wise at all times. ntp is
in the public doamin. archie can tell you where to get it.

Thanks also to Dan Strick, aka dan@bellcore.com for the following:

One cause of sparcstation time drift is failure to use a window
manager (e.g. sunview, openwindow, x11). The default console
terminal emulator is said to run interpreted Forth code very
slowly with all interrupts (including clock interrupts) turned off.

and to Kanthan Pillay <princeton!svpillay> for sending me the "README"
for the Network Time Protocol daemon source.



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