Monitoring domU real memory usage

Monitoring domU real memory usage

[bhavani krishnan]

Hi,

xentop is only giving me the memory allocated to the a domU (Static info). It does not change this info at all. Is there anyway to get how much of the allocated memory is the domU using? I saw few other similar posts in the archives but no solution to it. Please help me out here.

Thanks,
Bhavani

Re: Monitoring domU real memory usage

[Pasi Kärkkäinen]

On Thu, Oct 15, 2009 at 08:00:07PM -0700, bhavani krishnan wrote:
> Hi,
> 
> xentop is only giving me the memory allocated to the a domU (Static info). It does not change this info at all. Is there anyway to get how much of the allocated memory is the domU using? I saw few other similar posts in the archives but no solution to it. Please help me out here.
> 

Hi,

I don't know if that information is tracked.

Xen doesn't do memory overcommit, so it dedicates physical memory for
each guest, so it's up to the guests what they do with it.

-- Pasi

RE: Monitoring domU real memory usage

[Dan Magenheimer]

> On Thu, Oct 15, 2009 at 08:00:07PM -0700, bhavani krishnan wrote:
> > Hi,
> > 
> > xentop is only giving me the memory allocated to the a domU 
> (Static info). It does not change this info at all. Is there 
> anyway to get how much of the allocated memory is the domU 
> using? I saw few other similar posts in the archives but no 
> solution to it. Please help me out here.

You'll have to define more precisely what "using" means
since an OS "uses" (nearly) all the memory given to it for one
thing or another.  Are you referring to ballooning?

> I don't know if that information is tracked.
> 
> Xen doesn't do memory overcommit, so it dedicates physical memory for
> each guest, so it's up to the guests what they do with it.
> 
> -- Pasi

Xen CAN do memory overcommit, just not transparently (yet).

In the xen tree, see tools/xenballoond.  See this link
from Xen Summit 2008 for more description:

http://wiki.xensource.com/xenwiki/Open_Topics_For_Discussion?action=AttachFile&do=get&target=Memory+Overcommit.pdf

RE: Monitoring domU real memory usage

[Dan Magenheimer]

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This information is not available from domain0 by default but can be sent from each domU via xenstore.  Look at the shell scripts in xenballoond for an example of how to do that.  Basically, you need a shell script running in each domU to put the information (e.g. /proc/meminfo) into xenstore and a shell script in dom0 to read it and print it.
  -----Original Message-----
  From: bhavani krishnan [mailto:bhavi63@yahoo.com]
  Sent: Friday, October 16, 2009 8:46 AM
  To: Pasi Kärkkäinen; Dan Magenheimer
  Cc: xen-devel@lists.xensource.com
  Subject: RE: [Xen-devel] Monitoring domU real memory usage


        Precisely I want to know how much of the memory is free and active, like we get the mem usage % for apps from top in linux. Thanks, Bhavani

        --- On Fri, 10/16/09, Dan Magenheimer <dan.magenheimer@oracle.com> wrote:

        > From: Dan Magenheimer <dan.magenheimer@oracle.com>
        > Subject: RE: [Xen-devel] Monitoring domU real memory usage
        > To: ""Pasi Kärkkäinen"" <pasik@iki.fi>, "bhavani krishnan" <bhavi63@yahoo.com>
        > Cc: xen-devel@lists.xensource.com
        > Date: Friday, October 16, 2009, 2:53 PM
        > > On Thu, Oct 15, 2009 at
        > 08:00:07PM -0700, bhavani krishnan wrote:
        > > > Hi,
        > > > 
        > > > xentop is only giving me the memory allocated to
        > the a domU 
        > > (Static info). It does not change this info at all. Is
        > there 
        > > anyway to get how much of the allocated memory is the
        > domU 
        > > using? I saw few other similar posts in the archives
        > but no 
        > > solution to it. Please help me out here.
        > 
        > You'll have to define more precisely what "using" means
        > since an OS "uses" (nearly) all the memory given to it for
        > one
        > thing or another.  Are you referring to ballooning?
        > 
        > > I don't know if that information is tracked.
        > > 
        > > Xen doesn't do memory overcommit, so it dedicates
        > physical memory for
        > > each guest, so it's up to the guests what they do with
        > it.
        > > 
        > > -- Pasi
        > 
        > Xen CAN do memory overcommit, just not transparently
        > (yet).
        > 
        > In the xen tree, see tools/xenballoond.  See this
        > link
        > from Xen Summit 2008 for more description:
        > 
        > http://wiki.xensource.com/xenwiki/Open_Topics_For_Discussion?action=AttachFile&do=get&target=Memory+Overcommit.pdf
        >  


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RE: Monitoring domU real memory usage

[bhavani krishnan]

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Precisely I want to know how much of the memory is free and active, like we get the mem usage % for apps from top in linux.

Thanks,
Bhavani

--- On Fri, 10/16/09, Dan Magenheimer <dan.magenheimer@oracle.com> wrote:

> From: Dan Magenheimer <dan.magenheimer@oracle.com>
> Subject: RE: [Xen-devel] Monitoring domU real memory usage
> To: ""Pasi Kärkkäinen"" <pasik@iki.fi>, "bhavani krishnan" <bhavi63@yahoo.com>
> Cc: xen-devel@lists.xensource.com
> Date: Friday, October 16, 2009, 2:53 PM
> > On Thu, Oct 15, 2009 at
> 08:00:07PM -0700, bhavani krishnan wrote:
> > > Hi,
> > > 
> > > xentop is only giving me the memory allocated to
> the a domU 
> > (Static info). It does not change this info at all. Is
> there 
> > anyway to get how much of the allocated memory is the
> domU 
> > using? I saw few other similar posts in the archives
> but no 
> > solution to it. Please help me out here.
> 
> You'll have to define more precisely what "using" means
> since an OS "uses" (nearly) all the memory given to it for
> one
> thing or another.  Are you referring to ballooning?
> 
> > I don't know if that information is tracked.
> > 
> > Xen doesn't do memory overcommit, so it dedicates
> physical memory for
> > each guest, so it's up to the guests what they do with
> it.
> > 
> > -- Pasi
> 
> Xen CAN do memory overcommit, just not transparently
> (yet).
> 
> In the xen tree, see tools/xenballoond.  See this
> link
> from Xen Summit 2008 for more description:
> 
> http://wiki.xensource.com/xenwiki/Open_Topics_For_Discussion?action=AttachFile&do=get&target=Memory+Overcommit.pdf
> 


      

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