[ntp:questions] Flash 400 on all peers; can't get ntpd to be happy

Chris Albertson albertson.chris at gmail.com
Tue Mar 8 19:17:57 UTC 2011


On Tue, Mar 8, 2011 at 9:04 AM, Ralph <ralph at depth.net> wrote:
> I'm going to end this particular line of discussion because
> it is clear that this is a fruitless conversation and arguing
> back and forth about my personal ability to code a solution for
> VM time syncronization doesn't do anything for the problem at

No, the problem is not that no one can/will write the code.

Lets step away from computers and go back 300 years.  We'd have the
same problem if I had a clock that was so poor it would stop at random
times or even run backwards or instantly jump ahead.  Now I tell you
to look out the window at the big clock on the church tower and adjust
"fast/slow" lever on my poor clock.  OK so you do it as best you can
but then the clock stops for 5 minutes, so you push the lever to
full-speed fast then it catches up and over runs so you slow it again
only to find my cheap clock jumps 2 minutes ahead..   You will never
win.

We have the same EXACT problem.   If you can solve the above
mechanical clock problem then explain your solution to someone who CAN
code in C and he will be very happy to do it.   But so far most people
think that if the old clock is bad enough there is no possible
solution.

So I'll raise my hand.  I'll do it.  I right software like this all
day, every day 20+ years and counting.  You give me a fool-proof
solution to the 300 year old mechanical clock problem.   Tell me how
to adjust the fast/slow lever, prove that you are right and I'll write
the software.  We will both become heroes but I will give credit to
you.

OK there is a method that works on that old 300 year old clock.  Let
the spring wind doown so the clock stops.  Then every minute look out
the window and move the hands on my clock to match those on the clock
tower.  Yes you will keep busy but this works.   This is the method
you must use on your VM.  Just what everyone is saying -- you need to
get the time from the host OS and not try to let NTP adjust the rate
of the VM's clock as NTP will never win.


-- 
=====
Chris Albertson
Redondo Beach, California



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