[ntp:questions] iburst

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Mon Nov 27 17:45:01 UTC 2006


>I finally learned about ntpd about a week ago. It had been set to run by 
>the FC 5 installation. But the firewall prevented synch. When I finally 
>got that worked out, my boot time went from about 1 minute to many 
>minutes. In watching the boot messages, I discovered that ntpd was the 
>culprit. It takes ntpd several minutes to synch during boot. Was simply 
>trying to get that synch time down to something under 1 minute. During 
>the time I was trying to get ntpd through the firewall, someone on this 
>newsgroup mentioned using iburst to get the synch time from minutes to 
>seconds. Guess they had that wrong or we used different definitions of 
>synch.

There are two parts to getting ntpd started.  One is the startup
scripts that run automagically at boot time.  That shouldn't take
long as it forks off a deamon to do the real work.  I'd expect
a few seconds.

The other is for ntpd to get the clock in "sync".  With iburst,
that shouldn't take long, but I don't think you are waiting for
that.

I could easily be confused.  The details probably depend upon
your distribution.  Somebody might have tweaked things to wait
until ntp is in sync to make sure the log files are super accurate.

If I was annoyed with the startup times, I'd look carefully at the
startup scripts to see what it's doing.  Mine is in:
  /etc/rc.d/init.d/ntpd
If I couldn't see anything obvious, I'd make a copy and then
edit it to include printfs (aka things like: echo "step 1")
so I could figure out what it was doing.

You can probably experiment without rebooting with something like:
  service ntpd stop
  service ntpd start
(as root, obviously)

As somebody else suggested, there may be a ntpdate step in the
startup scripts.  That's a good candidate for taking a long
time, especially if you were having firewall troubles.

-- 
These are my opinions, not necessarily my employer's.  I hate spam.




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