timed

Thread View: comp.sys.sgi.admin

2 messages

[T] Back to Threads [V] Tree View [G] Group Articles

2 total messages Started by Neil J. Long Tue, 12 Jan 1993 09:43

#143

Author: Neil J. Long
Date: Tue, 12 Jan 1993 09:43

21 lines
1408 bytes

Hi
I have been trying to get a group of 5 Indigos to keep time and I have this 
slight problem with timed since there are a few other machines running timed 
but with the wrong time on the same network.
I have been using xntpd to keep one machine set right relative to 3 others 
sync'd to 3 other radio controlled beasts and that one machine is running 
timed -M -F localhost
So it should be master and not permit its clock to be changed other than by 
the xntpd daemon.
The problem is that for the other sgi's I cannot seem to start timed so that 
they listen only to the master and ignore the other ones on the net which 
are wrong.
The problem is that the other machines are in other departments, etc and 
their SuperUsers never seem to read their email form me suggesting they set 
their clocks (which would be pointless unless everyone can be reached and 
set all their clocks before re-starting timed).
Has anyone ever found a simple solution to this or do I need re-read the man 
pages!
Maybe if I define a 'network' such that the other machines aren't part of it?
thanks
Neil

Re: timed

#145

Author: Vernon Schryver
Date: Tue, 12 Jan 1993 17:17

42 lines
2316 bytes

In article <long.55.0@vax.ox.ac.uk>, long@vax.ox.ac.uk (Neil J. Long) writes:
> Hi
> I have been trying to get a group of 5 Indigos to keep time and I have this 
> slight problem with timed since there are a few other machines running timed 
> but with the wrong time on the same network.
> I have been using xntpd to keep one machine set right relative to 3 others 
> sync'd to 3 other radio controlled beasts and that one machine is running 
> timed -M -F localhost
> So it should be master and not permit its clock to be changed other than by 
> the xntpd daemon.
> The problem is that for the other sgi's I cannot seem to start timed so that 
> they listen only to the master and ignore the other ones on the net which 
> are wrong.
> The problem is that the other machines are in other departments, etc and 
> their SuperUsers never seem to read their email form me suggesting they set 
> their clocks (which would be pointless unless everyone can be reached and 
> set all their clocks before re-starting timed).
> Has anyone ever found a simple solution to this or do I need re-read the man 
> pages!
> Maybe if I define a 'network' such that the other machines aren't part of it?
> thanks
> Neil

Timed cannot solve such problems.  If all of the people operating a
single network cannot compromise on a single notion of "now", then you
cannot use timed.

Recall that the protocol used by timed, TSP, is a broadcast protocol.
It was designed to allow machines to discover the current time without
being especially configured to find a time master.

In such a crazy environment, where people cannot agree on the time, I
would use either (x)ntpd or timeslave instead of timed.

Please note that "master" is not quite the right word for the machine
that is averaging other machine's time.  "Moderator" is has much more
appropriate connotations.

Vernon Schryver,  vjs@sgi.com

Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads