Time Synchronizing Between Two Servers

[Jeffrey Goldberg]

On May 7, 2007, at 5:02 PM, RW wrote:

> If the time error is zeroed by ntpdate, and there's a drift-file, I
> don't see that the actual drift value makes much difference. I suspect
> that any quartz clock is overkill.

As someone already mentioned, drift data doesn't really solve the  
problem if the amount of drift varies (often with temperature, and  
sometimes dramatically with sleep).  The clock on my wife's G5 iMac  
seems to be erratic, but I haven't (and won't) bother to investigate  
further.  If her system is up to 2 seconds off for a bit after waking  
from sleep, so be it.  (If I ever start using kerberos around the  
house, I will have to address that.)

If a machine is up for months, ntpdate may have been run in the  
distant past, so you can still a fair amount of error.

ntpd is really a very light weight thing.  When things are ticking  
over nicely, it may make just one query every few hours and still  
keep very good time.

Also, if you have a server facing the Internet, you may wish to run a  
public NTP service on it and contribute it to pool.ntp.org, see

  http://www.pool.ntp.org/join.html

for info.

-j


-- 
Jeffrey Goldberg                        http://www.goldmark.org/jeff/