All of lore.kernel.org
 help / color / mirror / Atom feed
* Question about suspended virtual machine resources on a kvm hypervisor
@ 2014-03-10 20:33 William Heath
  2014-03-11  7:49 ` Paolo Bonzini
  0 siblings, 1 reply; 4+ messages in thread
From: William Heath @ 2014-03-10 20:33 UTC (permalink / raw)
  To: kvm

Hi All,

I am working with OnApp for a cloud solution.  In order to do billing
correctly, I am curious what resources are freed up when a virtual
machine is suspended on a kvm hypervisor.  Are cpu, ram, and disk all
freed up or what is reallocated to other virtual machines etc...?

-Tim

P.S.

Thanks sooo much for this help :>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Question about suspended virtual machine resources on a kvm hypervisor
  2014-03-10 20:33 Question about suspended virtual machine resources on a kvm hypervisor William Heath
@ 2014-03-11  7:49 ` Paolo Bonzini
  2014-03-11  8:10   ` William Heath
  0 siblings, 1 reply; 4+ messages in thread
From: Paolo Bonzini @ 2014-03-11  7:49 UTC (permalink / raw)
  To: William Heath, kvm

Il 10/03/2014 21:33, William Heath ha scritto:
> Hi All,
>
> I am working with OnApp for a cloud solution.  In order to do billing
> correctly, I am curious what resources are freed up when a virtual
> machine is suspended on a kvm hypervisor.  Are cpu, ram, and disk all
> freed up or what is reallocated to other virtual machines etc...?

A suspended VM uses no CPU.  It still uses RAM, and files are still open 
even though no I/O should happen.

Paolo


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Question about suspended virtual machine resources on a kvm hypervisor
  2014-03-11  7:49 ` Paolo Bonzini
@ 2014-03-11  8:10   ` William Heath
  2014-03-11  8:37     ` Paolo Bonzini
  0 siblings, 1 reply; 4+ messages in thread
From: William Heath @ 2014-03-11  8:10 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: kvm

So is the CPU re-allocated to other virtual machines that need them?
I take it then that RAM and disk usage are not reallocated?

-Tim

On Mon, Mar 10, 2014 at 9:49 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Il 10/03/2014 21:33, William Heath ha scritto:
>
>> Hi All,
>>
>> I am working with OnApp for a cloud solution.  In order to do billing
>> correctly, I am curious what resources are freed up when a virtual
>> machine is suspended on a kvm hypervisor.  Are cpu, ram, and disk all
>> freed up or what is reallocated to other virtual machines etc...?
>
>
> A suspended VM uses no CPU.  It still uses RAM, and files are still open
> even though no I/O should happen.
>
> Paolo
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Question about suspended virtual machine resources on a kvm hypervisor
  2014-03-11  8:10   ` William Heath
@ 2014-03-11  8:37     ` Paolo Bonzini
  0 siblings, 0 replies; 4+ messages in thread
From: Paolo Bonzini @ 2014-03-11  8:37 UTC (permalink / raw)
  To: William Heath; +Cc: kvm

Il 11/03/2014 09:10, William Heath ha scritto:
> So is the CPU re-allocated to other virtual machines that need them?

In KVM, virtual CPUs are just threads; if a thread does not want to run, 
the Linux scheduler does not give it any CPU.  If the virtual machine 
monitor you're using is QEMU, the virtual CPU threads of a suspended VM 
will be waiting on a condition variable until the VM is resumed.

> I take it then that RAM and disk usage are not reallocated?

No.  But RAM can be swapped out, for both suspended and running VMs.

Paolo

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2014-03-11  8:37 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-03-10 20:33 Question about suspended virtual machine resources on a kvm hypervisor William Heath
2014-03-11  7:49 ` Paolo Bonzini
2014-03-11  8:10   ` William Heath
2014-03-11  8:37     ` Paolo Bonzini

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.