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From: Harald Koenig <H.Koenig@science-computing.de>
To: Saku Ytti <saku@ytti.fi>
Cc: Harald Koenig <H.Koenig@science-computing.de>,
	xen-devel@lists.xensource.com
Subject: Re: domU clock over 23s off
Date: Wed, 12 Jul 2006 21:46:03 +0200	[thread overview]
Message-ID: <20060712194603.GA29131@atuin.science-computing.de> (raw)
In-Reply-To: <20060712134308.GA5475@mx.ytti.net>

On Jul 12, Saku Ytti wrote:

> On (2006-07-12 15:37 +0200), Harald Koenig wrote:
>  
> > does running ntp in a domU disable the clock synchronisation between dom0 and domU ?
> 
> I do this:
> [ytti@ytti.fi ~]% ssh root@herra.ip.fi "cat /etc/cron.hourly/ntp-hack"
> #!/bin/sh
> 
> PATH=/bin
> 
> date -s $(date +%H:%M:%S) > /dev/null

thanks for the hint!  

indeed, running this on dom0 also sets the clocks for domU.


BUT: it also causes clock jumps up to 0.999 secs every our because it can't 
handle fractions of a second.   and it always steps back the time
giving a non-monotonic system time -- too bad :-(((

that's not what time syncronisation and ntp is all about...


I tried to keep the fractions of seconds but this doesn't work:

	# date -s $( date +%H:%M:%S.%N )
	date: invalid date `21:38:53.976633000'


are there other methods  to trigger the time sync (push) between 
dom0 and domU without (re-) setting the system time in dom0 ? 


looks like I have to live with a jumpy time for now :-(


thanks for your help,

Harald Koenig
-- 
"I hope to die                                      ___       _____
before I *have* to use Microsoft Word.",           0--,|    /OOOOOOO\
Donald E. Knuth, 02-Oct-2001 in Tuebingen.        <_/  /  /OOOOOOOOOOO\
                                                    \  \/OOOOOOOOOOOOOOO\
                                                      \ OOOOOOOOOOOOOOOOO|//
Harald Koenig                                          \/\/\/\/\/\/\/\/\/
science+computing ag                                    //  /     \\  \
koenig@science-computing.de                            ^^^^^       ^^^^^

  reply	other threads:[~2006-07-12 19:46 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-02-26 10:07 domU clock over 23s off Saku Ytti
2006-02-26 10:20 ` Saku Ytti
2006-02-26 10:21 ` Saku Ytti
2006-02-26 14:47 ` Keir Fraser
2006-02-26 15:47   ` Keir Fraser
2006-02-26 15:51     ` Saku Ytti
2006-02-26 15:52     ` Saku Ytti
2006-07-12  9:00   ` Harald Koenig
2006-07-12  9:25     ` Keir Fraser
2006-07-12  9:56       ` Harald Koenig
2006-07-12 10:42         ` Keir Fraser
2006-07-12 13:37           ` Harald Koenig
2006-07-12 13:43             ` Saku Ytti
2006-07-12 19:46               ` Harald Koenig [this message]
2006-07-13  8:17                 ` Keir Fraser
2006-07-13 10:05                   ` Harald Koenig
2006-02-26 23:55 ` James Henderson
2006-02-27  6:19   ` Saku Ytti
  -- strict thread matches above, loose matches on Subject: below --
2006-11-13 22:49 Alexander Vallens

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