I have also noticed the problem that domains take much longer to
migrate if they are set to have memory < maxmem. I know this was a
problem back in the Xen 3.0.1 days and had thought I had heard that it
was getting fixed with newer versions.
At that time if you looked at one of the xen debug logs there were
millions of lines of errors every time you attempted to migrate a
domain which had its memory image shrunk... I would suggest that you
check if your current setup is also producing this kind of output and
search for that error message -- I know there were some messages on
this mailing list about it in the past, but can't find them right now.
good luck!
On 8/10/07, Marconi Rivello <marconirivello@xxxxxxxxx> wrote:
>
>
> On 8/10/07, Luciano Rocha <strange@xxxxxxxxxxxxx> wrote:
> > On Fri, Aug 10, 2007 at 02:18:53PM -0300, Marconi Rivello wrote:
> > > Hi, Luciano.
> > >
> > > On 8/10/07, Luciano Rocha <strange@xxxxxxxxxxxxx> wrote:
> > > >
> > > > On Fri, Aug 10, 2007 at 12:42:08PM -0300, Marconi Rivello wrote:
> > > > > Another issue that I described on a previous email (which,
> > > > unfortunately,
> > > > > didn't get any replies) is that this downtime increases to more than
> 20
> > > > > seconds if I set the domU's memory to 512MB (the maxmem set is
> 1024MB).
> > > > I
> > > > > repeated the test successively, from one side to the other, with mem
> set
> > > > to
> > > > > 512 and 1024, and the result was always the same. Around 3s with mem
> =
> > > > > maxmem, and around 24s with mem=512 and maxmem=1024.
> > > > >
> > > >
> > > > You are using the option --live to migrate, aren't you?
> > >
> > >
> > > Yes, I am. :)
> >
> > Oh. Well, then, could you try without? :)
>
> I could, but what I'm whining :) about is to have a period of
> unresponsiveness of a couple of seconds, instead of a tenth of a second. If
> I do a stop-copy-restart migration it will be even longer.
>
> > Also, try the reverse. Ping an outside host in the domU.
>
> I will. In fact, I will try all the monitoring suggestions (from you and
> the others). Inside domU, outside, third machine, ICMP, ARP...
>
> > > Even if I weren't, it would make sense to expect a lower downtime (or
> the
> > > same downtime) by reducing the domU memory. But it takes longer if I
> reduce
> > > the domU's memory.
> >
> > That is odd. Is the Dom0 memory the same (ie., fixed)?
> >
> > > Would you happen to have any ideas on why it behaves like that?
> >
> > No idea. I might expect a longer migration time for a machine with a
> > very active working set, but not a much longer downtime. That should be
> > only a freeze, final sync, and resume on the other side.
> >
> > --
> > lfr
> > 0/0
> >
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-users
> >
> >
>
>
> I would like to thank everyone who contributed with ideas. It was very
> helpful. Unfortunately, I will be gone for the next week on a training, and
> will only be able to further investigate when I get back to work. When I do,
> I will do some more tests and post what I find out or not.
>
> Thanks again,
> Marconi.
>
> _______________________________________________
> 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
|
Home