[one-users] Beginner questions: Opennebula 2.2.1

[Tino Vazquez]

Hi Peter,


On Wed, May 4, 2011 at 7:42 AM, Peter Farič <peter.faric at ledinek.com> wrote:
> Hi,
>
>
> I'm mostly using the CLI, but through Sunstone I can explain it best.
>
> In Sunstone when you shutdown a VM, then the VM entry disappears. If I want
> to run the same VM later I have to go through the same process of creating
> the VM like the first time. In the CLI I understand I use the same VM
> template file to create the same VM again. Is this the way its supposed to
> work or will future versions have some sort of mechanism to deal with this
> use case (on the mailing list I read something about a VM template pool)?

Yes, upcoming ONE release will ship with a Template Pool, to be able
to instantiate VMs from predefined templates.

> From a users perspective there is no real difference betwen onevm delete and
> onevm shutdown - they both make a previously running VM inaccessible...
> Maybe a better question would be - how do you use Opennebula?

Delete a VM is like unplugging the power cord (the FS can break), adn
plus the image is not transfered back (even if the SAVE flag is
present). Shutdown represents a more clean approach, the VM is cleanly
shut down, and the image saved if marked so.

>
> What if I wanted to create new VMs on the fly if network traffic were to
> spike? As I understand it I would make hooks and if some monitored value
> exceeded the threshold it would run create on an VM template file. Is this
> correct?

For this use case, you will need an (easily to develop) new component,
a Service Manager, that will use values from ONE monitoring to decide
to launch or shutdown VMs.

>
>
> At our company we have 10 dedicated servers for virtualization which share a
> SAN. I plan on running 30 - 40 VMs. Mostly Linux.
>
> Is Opennebula a good fit for our scenario?

I would say it is ;)

>
>
>
> Thanks!


Regards,

-Tino

--
Constantino Vázquez Blanco | dsa-research.org/tinova
Virtualization Technology Engineer / Researcher
OpenNebula Toolkit | opennebula.org


>
>
> Sincerely,
> Peter Farič
>
> Neumann, Steffen wrote:
>>
>> Hi,
>>
>> I think you understood things correctly,
>> in ONE you create and shutdown instances, and you get new VM IDs for every
>> cycle.
>>
>> So in our HPC setup, we get "fresh" virtual compute nodes with every onevm
>> create.
>> What exactly do you want ? Do you need the changes to be persistent ?
>>
>> yours,
>> Steffen
>> ________________________________________
>> From: users-bounces at lists.opennebula.org
>> [users-bounces at lists.opennebula.org] on behalf of Peter Farič
>> [peter.faric at ledinek.com]
>> Sent: 03 May 2011 12:57
>> To: users at lists.opennebula.org
>> Subject: [one-users] Beginner questions: Opennebula 2.2.1
>>
>> Hi!
>>
>>
>> I'm experimenting with opennebula 2.2.1 on Centos 5.5 i686. So far I am
>> pleased with the results. I got two KVM nodes and am running two VMs.
>>
>> Since I am a beginner I can't seem to wrap my head around the lifecycle
>> of VMs. I looked at the documentation and the shown lifecycle... When I
>> shutdown a VM instance it is not shown in "onevm list" anymore. I read
>> that this is normal. If I then want to start it again I have to run
>> "onevm create centos.one" which is ok, but how do I automate this
>> process so oned can start it on its own or am I missing something? I am
>> used to the way virt-manager does things as it leaves an entry for a VM
>> instance even if its shutdown and keeps the VM ID number... Any thoughts
>> on this?
>>
>> One other thing is when I have a VM running on a node and I run
>> "poweroff" in the VM instance, the VM shuts down and the nodes "virsh
>> list" shows the VM as not running anymore. On the "oned" server "onevm
>> list" still shows the VM instance as running. Shouldn't it recognize the
>> new state of the VM and report something?
>>
>>
>>  Thanks!
>>
>>
>> --
>>
>> LP,
>> ---------------------------------------
>> Peter Farič
>> Sistemski administrator
>> Tel.:  +386 2 613 00 79
>> Fax :  +386 2 613 00 60
>> Email: peter.faric at ledinek.com
>> WWW:   http://www.ledinek.com
>> Ledinek Engineering d.o.o.
>> Bohovska cesta 19 A
>> SI-2311 HOČE
>> Slovenija
>> ---------------------------------------
>>
>> _______________________________________________
>> Users mailing list
>> Users at lists.opennebula.org
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>>
>>
>
> --
>
> LP,
> ---------------------------------------
> Peter Farič
> Sistemski administrator
> Tel.:  +386 2 613 00 79
> Fax :  +386 2 613 00 60
> Email: peter.faric at ledinek.com
> WWW:   http://www.ledinek.com
> Ledinek Engineering d.o.o.
> Bohovska cesta 19 A
> SI-2311 HOČE
> Slovenija
> ---------------------------------------
>
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