RE: [Xen-users] NTP time issues DomU's

["Ian Pratt" <m+Ian.Pratt@xxxxxxxxxxxx>]

> yeah, i'm already doing that, I was just saying, it *seemed* 
> like they were getting their time from domain0, and weren't 
> actually changing their own clocks in accordance with syncing 
> with the same ntpd server.
 
> especially since they're all off by exactly the same amount 
> ... and running ntpdate doesn't seem to have any effect whatsoever?

If you don't run ntp in the domU's, it should just work.

If you want to run ntp in the domU, try:
 echo 1 > /proc/sys/xen/independent_wallclock

I guess we could be smarter about this, and make the wall clock
independent automatically if someone does an adjtimex syscall. Anyone
got any comments on this?

Ian

 
> On Thu, 12 May 2005, Fernando Maior wrote:
> 
> > On 5/12/05, andrew mathes <amathes@xxxxxxxxxxxx> wrote:
> >> don't the DomU's just get their time from DomO?  Ie. ... 
> even if they 
> >> weren't running ntp they'd always be synced with whatever DomO 
> >> thought about system time?
> >>
> >> Maybe i'm way off
> >>
> >> On Thu, 12 May 2005, Alex Tomkins wrote:
> >>
> >>> On Thu, May 12, 2005 at 10:42:53AM -0700, andrew mathes wrote:
> >>>> So, from what it looks like (on my servers and the docs), all my 
> >>>> domains get their time from DomO.  Which I have setting itself 
> >>>> through NTP, and the dom0 looks good.  However, All of 
> the domains 
> >>>> are 1.5 seconds off, and won't ntp themselves on, also, an 
> >>>> identical server, all the domains are
> >>>> .768 seconds off (off of the server i'm ntping to) , but both 
> >>>> domO's are withing (.02) and seem to narrow in as NTP is 
> supposed to.
> >>>>
> >>>> So, question is, 1) what is going on here, and 2) can 
> anything be 
> >>>> done about it?
> >>> Are you using OpenNTPD by any chance?
> >>> My machines suffered from inaccurate clocks in DomU's, 
> even though 
> >>> the clock was very accurate in Dom0.  Switching to regular ntpd 
> >>> solved this, DomU immediately used the correct time 
> shortly after starting ntpd.
> >>> --
> >>> Alex Tomkins <tomkins@xxxxxxxxxxxx>
> >
> > Andrew,
> >
> > Please remember, you allways shoult treat each virtual 
> machine like a 
> > completely separated host! So far, you shoul configure ntpd to get 
> > time from -possibly- the same host as you dom0 is getting time. Try 
> > that. It won't hurt :) And I bet you will feel happy with 
> the result 
> > :)
> >
> > --
> > Bye,
> > Fernando Maior
> > LPIC/1 31908
> >
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-users
> >
> 
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
> 

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users