libvirt users - Jul 2014 - Re: memoryStats question

At Thu, 3 Jul 2014 15:58:41 +0200,
Martin Kletzander wrote:
> 
> On Thu, Jul 03, 2014 at 04:31:46PM +0300, Gleb Voronich wrote:
> >Hello,
> >
> >I'm trying to get memory usage statistic inside a guest machine
using
> >virDomainMemoryStats function at libvirt.
> >According to
> >http://libvirt.org/html/libvirt-libvirt.html#virDomainMemoryStatTags
the
> >structure could have a lot of useful memory statistic but the amount of
> >parameters depends on the hypervisor and the driver.
> >However using KVM I'm able to get
VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON
> >and VIR_DOMAIN_MEMORY_STAT_RSS only.
> >
> 
> QEMU/KVM only supports these two IIRC.
Actually, you should get more stats when using the virtio balloon
driver in your guests.

E.g. the windows virtio driver supports these stats:

SWAP_IN  0   /* Amount of memory swapped in */
SWAP_OUT 1   /* Amount of memory swapped out */
MAJFLT   2   /* Number of major faults */
MINFLT   3   /* Number of minor faults */
MEMFREE  4   /* Total amount of free memory */
MEMTOT   5   /* Total amount of memory */

See
https://github.com/YanVugenfirer/kvm-guest-drivers-windows/blob/9a5cb6749d68bad8c346d31b811c854ab078652e/Balloon/sys/public.h

IFAIR, these should be queried by the virDomainMemoryStats function.

Claudio
-- 
BSc (Comp) Claudio Bley - Principal Software Engineer
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> Actually, you should get more stats when using the virtio balloon
> driver in your guests.
I use the balloon but I can't get more stats.
I use python binding for libvirt and as far as I can see it calls 
virDomainMemoryStats exactly.

At Thu, 03 Jul 2014 17:32:20 +0300,
Gleb Voronich wrote:
> 
> 
> > Actually, you should get more stats when using the virtio balloon
> > driver in your guests.
> I use the balloon but I can't get more stats.
> I use python binding for libvirt and as far as I can see it calls
> virDomainMemoryStats exactly.
Which OS are you using in your guests?

Of course, you need to have the virtio balloon driver up and runnig in
your guests.

Claudio