[ntp:questions] NTP - best practice if there is a local stratum 2 server

Dave foo at coo.com
Sun Jun 28 16:19:14 UTC 2009

I'm trying to set up the time on a couple of machines at the University 
of Washington and have tried two ways:

1) Sync both to the ntp pool - not very successful, as they kept 
differing by enough to cause 'make' to say files were created in the 
future by a few ms - no doubt due the NFS exported drives.

2) Set one via ntpd (call is master) from the ntp pool, then the other 
local machine (slave) read the time from the master. That appears to 
work quite well. They at least agree on the time pretty closely now. The 
absolute accuracy might not be as good as possible with a local time 
server, but for practical purposes it works well.

Searching around, I found that the university does in fact have their 
own strtatum 2 time server - I assume in another department to where the 
machines I'm using are located. The server is


I assume, for absolute accuracy (which is not important here, but I'm 
intersted), this is going to be better than any attempt to set the time 
from the ntp pool. Is that correct?

But setting the time from the local server is also going to be cause a 
problem if that server fails for some reason.

Is there any way to make use of a local server if it's working, and then 
use the pool if its not?

To be honest, this is all a bit academic, as there is no real practical 
need to have an accuracy of better than a minute or two on these 
machines. In fact, an hour wrong would not make much difference but it 
might irritate a few people.

But it is important the two machine agree with each other, as otherwise 
files appear to be created in the future by a few ms, which screws up 
the 'make' program some times.

I respectfully request that this message is not archived by companies as
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idiots stupid enough to pay for the answers, which were posted freely
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