Subject: Re: dom0 and timed
To: Daniel Hagerty <hag@linnaean.org>
From: Sarton O'Brien <bsd-xen@roguewrt.org>
List: port-xen
Date: 02/06/2008 12:43:08
Daniel Hagerty wrote:
>  > OK, I understand now ... so assuming timed is still relevant ...
>  > wouldn't you need a master time source using ntpd to synchronise time
>  > with and wouldn't that source require a master timed service so that
>  > clients can synchronise an accurate time?
> 
>     In the days when timed was common, master clocks would be adjusted
> to real world time via other methods -- dialing NIST, set by
> wristwatch, what have you.  Aside from the periodic slew by an
> administrator, timed owns the clock.
> 
>     AFAIK, timed does not have a mode for "something else owns the
> system clock, only speak network protocol to clients".

OK, just so you know I'm not crazy, the last paragraph of the netbsd 
guide states:

	NTP is not your only option if you want to synchronize your network: 
you can also use the timed  daemon or the rdate(8) command as well. 
timed was developed for 4.3BSD.

	Timed too uses a master-slave hierarchy: when started on a host, timed 
asks the network time to a master and adjusts the local clock 
accordingly. A mixed structure, using both timed and ntpd can be used. 
One of the local hosts gets the correct time from a public NTP server 
and is the timed master for the remaining hosts of network, which become 
its clients and synchronize their clocks using timed. This means that 
the local server must run both NTP and timed; care must be taken that 
they don't interfere with each other (timed must be started with the -F 
hostname option so that it doesn't try to adjust the local clock).

>     BTW, for the problem with interfaces, try playing with the
> --updateinterval flag.

I'll give it a go.