[ntp:questions] ntpd, boot time, and hot plugging

Brad Knowles brad at stop.mail-abuse.org
Fri Feb 4 00:20:14 UTC 2005

At 11:45 PM +0000 2005-02-03, Per Hedeland wrote:

>>	But how many people actually use ntpdate to check more than one
>>  upstream?
>  I mentioned multiple servers just for completeness

	If it's not the typical mode of use for the program, then it's 
not particularly interesting.

>          Anyway, I surely don't have any numbers for that, but I would
>  expect it to be pretty close to the number of people that have more than
>  one server in their ntp.conf - which is almost certainly a minority
>  outside the readers of this newsgroup.

	Close?  No.  Absolutely not.  There are a number of projects that 
now ship ntp.conf files pre-built that use multiple servers, and many 
people will use these operating systems without any knowledge of NTP.

	Perhaps a small fraction of the people who use multiple servers 
in their ntp.conf may also do something comparable with ntpdate.  But 
only a very small fraction.

>>	It's not a matter of what ntpdate is capable of, if used in the
>>  correct way.  It's a matter of the way in which ntpdate is typically
>>  used.
>  Well, there was certainly no indication that this was what you were
>  talking about in the previous post.

	My apologies.  There are so many weaknesses in ntpdate that it's 
hard to enumerate them all, and it's hard to start discussing some of 
them without also getting pulled into discussing the others.

>                                    The question (if any) is how ntpd
>  compares to ntpdate for doing what ntpdate does - all that is desired is
>  to quickly bring the clock well within the 128 ms range, so as to allow
>  ntpd to keep it in check without steps from then on.

	I think this question has been answered.

	With regards to quick startup, can we do a better job with ntpd 
than we do today?  I believe so, yes.

	Does ntpd do a sufficiently good job today?  Again, I think it's 
hard to argue otherwise.

Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.

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