[one-users] resume a suspended VM in a different host

[Shi Jin]

Very helpful information.
And I should add a comment that with shared storage (NFS), the
stop/resume is also very fast.

Thanks a lot.
Shi

On Thu, Apr 29, 2010 at 7:06 AM, Ruben S. Montero <rubensm at dacya.ucm.es> wrote:
> Hi
>
> There are two different ways to stop a VM:
>
> suspend: It leaves the images and checkpoint files in the running
> host, as you describe in your email. When you resume the VM all the
> files are already there and it should be fast. You usually want to use
> suspend for short suspend cycles.
>
> stop: It moves the files back to the VM_DIR. When you resume a stopped
> VM it will be re-scheduled and likely it will be re-started in other
> host. Note that is a more expensive process as images have to be moved
> between hosts.
>
> I think that stop is the behavior you were looking for...
>
> Cheers
>
> Ruben
>
> On Tue, Apr 27, 2010 at 1:35 AM, Shi Jin <jinzishuai at gmail.com> wrote:
>> Hi there,
>>
>> I am able to suspend/resume a KVM instance using OpenNebula, which is very nice.
>> However, I find that the resumed VM always runs on the same host where
>> it was running before.
>> This pauses a problem if the original host became fully occupied. The
>> VM will resume any ways, causing degradation of performance of other
>> VMs and might even cause error due to lack of memory.
>> On the other hand, I think this can be fixed, especially if we are
>> using a shared storage driver such as the tm_nfs.
>> I can imagine that the to be resumed VM is actually put into the queue
>> asking for resources from the scheduler.
>> Once a proper host is selected for it, it can then easily be resume
>> from the other host.
>>
>> I guess we don't really have to have a shared storage, just like
>> migrate works on ssh drivers as well.
>>
>> Do you think this is a reasonable suggestion?
>>
>> --
>> Shi Jin, Ph.D.
>> _______________________________________________
>> Users mailing list
>> Users at lists.opennebula.org
>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>>
>
>
>
> --
> Dr. Ruben Santiago Montero
> Associate Professor (Profesor Titular), Complutense University of Madrid
>
> URL: http://dsa-research.org/doku.php?id=people:ruben
> Weblog: http://blog.dsa-research.org/?author=7
>



-- 
Shi Jin, Ph.D.