WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] out-of-memory problem when restoring ballooned domains

To: Mark Williamson <Mark.Williamson@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] out-of-memory problem when restoring ballooned domains
From: Lars Rasmusson <Lars.Rasmusson@xxxxxx>
Date: Thu, 10 Mar 2005 10:54:38 -0800
Cc: xen-devel <Xen-devel@xxxxxxxxxxxxxxxxxxxxx>
Delivery-date: Thu, 10 Mar 2005 18:55:32 +0000
Envelope-to: xen+James.Bulpin@xxxxxxxxxxxx
In-reply-to: <200503101839.12054.maw48@xxxxxxxxxxxx>
List-archive: <http://sourceforge.net/mailarchive/forum.php?forum=xen-devel>
List-help: <mailto:xen-devel-request@lists.sourceforge.net?subject=help>
List-id: List for Xen developers <xen-devel.lists.sourceforge.net>
List-post: <mailto:xen-devel@lists.sourceforge.net>
List-subscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=subscribe>
List-unsubscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=unsubscribe>
Organization: HP Labs, Palo Alto, CA
References: <1110480173.11317.3.camel@xxxxxxxxxxxxxxx> <200503101839.12054.maw48@xxxxxxxxxxxx>
Sender: xen-devel-admin@xxxxxxxxxxxxxxxxxxxxx
It seems to compute it just right...


# xm list
Name              Id  Mem(MB)  CPU  State  Time(s)  Console
Domain-0           0      123    0  r----    330.2        
t1                19      128    0  -b---      0.0    9619
t2                20      128    1  -b---      0.0    9620

# xm info
system                 : Linux
host                   : hpl1-024-01-eth0.hpl.hp.com
release                : 2.6.10-xen0
version                : #1 Thu Mar 10 09:42:16 PST 2005
machine                : i686
cores                  : 2
hyperthreads_per_core  : 1
cpu_mhz                : 1000
memory                 : 2047
free_memory            : 1639

# xm restore t3.saved
Error: 1

# xm save t1 t1.saved
# xm save t2 t2.saved
# xm restore t3.saved

# xm list
Name              Id  Mem(MB)  CPU  State  Time(s)  Console
Domain-0           0      123    0  r----    347.4        
t3                22      128    0  -b---      0.0    9622


So all domains have 128 Mb, and xen seems to count the memory fine...

(FYI I'm using xen-2.0-testing, checked out from bitkeeper this morning)


On Thu, 2005-03-10 at 18:39 +0000, Mark Williamson wrote:
> Can you show us the output of xm list after the restore failure?  It'd be 
> interesting to see how much memory Xen thinks the domains are occupying.
> 
> Cheers,
> Mark
> 
> On Thursday 10 March 2005 18:42, Lars Rasmusson wrote:
> > Hi,
> >
> > I have a problem with the balloon functionality.
> >
> > I have a 2G memory machine (with 2 CPUs).
> >
> > I want to create three (or more) user domains,
> > each configured to have 2G (or 1800MB) of RAM,
> > but ballooned down to 128 MB.
> >
> > The reason is that I want to be able to change the
> > size of the balloons during run time, and I want
> > each of the domains to be able to potentially get
> > all (or almost all) of the memory.
> >
> > I first create the domains t1, t2, and t3:
> >
> > xm create t1 memory=1800
> > xm balloon t1 128
> > # wait until the balloon is inflated
> > xm save t1 t1.saved
> >
> > and repeat for t2 and t3.  Notice that I can
> > create the domains with maximum memory since
> > the other domains are not using any RAM at
> > the time.
> >
> > Here comes my problem:
> >
> > When I do
> >
> > xm restore t1.saved
> > xm restore t2.saved
> > xm restore t3.saved
> >
> > I get "Error: 1" when I create the third
> > domain.  I get the feeling it has something to
> > do with "not enough memory" (is that  correct?)
> >
> > So even though the three 128 Mb domains should
> > fit easily within the approx 2G RAM, Xen doesn't
> > think so.  Which is why I've come to think there
> > might be some problem with how it is counting available RAM.
> >
> > - Is Xen taking ballooned memory into account properly?
> >
> > - Is it interpreting the info in the .saved file correctly?
> >
> > If that is the bug, I then wonder why I'm able to get two
> > user domains up and running, and not just one...
> > Could that be related to that the machine is a 2 CPU machine?
> >
> > Well that's just speculation... Does anyone have any
> > suggestions what I might be doing wrong, or where the
> > problem may be?
> >
> > Cheers,
> > Lars Rasmusson
> >
> >
> >
> >
> >
> >
> > -------------------------------------------------------
> > SF email is sponsored by - The IT Product Guide
> > Read honest & candid reviews on hundreds of IT Products from real users.
> > Discover which products truly live up to the hype. Start reading now.
> > http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.sourceforge.net/lists/listinfo/xen-devel
> 
> 
> -------------------------------------------------------
> SF email is sponsored by - The IT Product Guide
> Read honest & candid reviews on hundreds of IT Products from real users.
> Discover which products truly live up to the hype. Start reading now.
> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.sourceforge.net/lists/listinfo/xen-devel


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel