[one-users] Simplified VM creation?

Pentium100 pentium100 at gmail.com
Tue Sep 10 04:48:04 PDT 2013


While we use hypervisors with local storage, the images has to be
persistent. As I said, it should not be easy to lose data. Right now, the
users do not get access to the VM controls (a simple libvirt setup with
virt-manager and local logical volumes for storage) but even for me or some
other admin it would be difficult to delete the data from the GUI -
deleting the virtual machine leaves the logical volume with the data.

OpenNebula would allow us to allow the users themselves to control their
VMs - however, losing data with a couple of clicks (oops, selected
"delete/recreate" instead of "reboot hard") is too dangerous. Using
persistent images makes it multiple clicks to actually lose data (delete
the VM then delete the image) which greatly reduces the probability of an
accident. Just like is is rather difficult to lose the data of a real
server by accident.

I understand the need for non-persistent images in case of scale-out or
similar when you need many identical VMs that do not have any data (the
data is stored elsewhere), but our clients only use VDS - each VM is a
unique server and losing its data is bad.


On Tue, Sep 10, 2013 at 2:32 PM, Campbell, Bill <
bcampbell at axcess-financial.com> wrote:

> I agree on the non-persistent images, so long as you are careful it
> shouldn't be a problem.  I understand their purpose, and for particular use
> cases (development environments, hypervisors with local rather than shared
> storage) they make sense.  I compare non-persistent images to instance
> store EC2 instances.  Once you shut them down, they are pretty much gone
> for good, and they are not as versatile or forgiving as EBS backed images.
>
> As an aside, I think that the terminology used in the instance lifecycle
> should be modified to better match the function.  When you want to destroy
> an instance, use "destroy" and "terminate" rather than 'delete' and
> 'shutdown' (the new sunstone interface shows the trash can, which is a good
> indicator of what you want to do).  This can be confusing if familiar with
> or have managed/integrated an EC2 environment.
>
> ------------------------------
> *From: *"Pentium100" <pentium100 at gmail.com>
> *To: *"Daniel Molina" <dmolina at opennebula.org>
> *Cc: *users at lists.opennebula.org
> *Sent: *Tuesday, September 10, 2013 3:27:50 AM
> *Subject: *Re: [one-users] Simplified VM creation?
>
>
> Hi,
>
> I upgraded to 4.2 and the cloud view is quite nice. I modified the user
> view to include the easy provisioning (for some reason "create image" does
> not work in cloud view, even if I enable it) and now it is pretty much like
> it should be - the user can create a persistent image (or clone a provided
> one) and set up a VM (either using a provided template or creating his own).
>
> Non persistent images are dangerous - it's almost like using volatile
> memory instead of HDD or SSD in a real server - one simple mistake
> (clicking shutdown instead of standby/pause) and you now have to restore
> the backup. It should not be easy to lose data.
>
>
> On Thu, Sep 5, 2013 at 12:53 PM, Daniel Molina <dmolina at opennebula.org>wrote:
>
>> Hi,
>>
>>
>> On 4 September 2013 13:30, Pentium100 <pentium100 at gmail.com> wrote:
>>
>>> Hello,
>>>
>>> While trying out OpenNebula, I noticed that the VM creation process is
>>> quite inconvenient if I want different VMs (as opposed to scaleout
>>> situation).
>>>
>>> 1. Create the image (upload a new one or copy some other image), set it
>>> as persistent (I don't want the VM to disappear if I shut it down).
>>> 2. Create a template that uses the image.
>>> 3. Finally create a VM from the template. There will only be one VM
>>> using that template (because I don't really need two identical VMs).
>>>
>>> To create 10 virtual servers (all the same "hardware" but different
>>> images) I need to repeat steps 1-3 ten times.
>>>
>>> It would be nice, if there was a way to simplify this. I can think of 3
>>> ways to do it:
>>>
>>> 1. Skip the creation of a template. Create an image then create a VM
>>> based on that image.
>>> 2. Do not define an image while creating a template. Assign the image
>>> when creating the VM.
>>>  3. Have some "template" image that gets copied when a VM is created.
>>> The copy should be persistent.
>>>
>>> Is there a way to do it? Non-persistent images behave almost like option
>>> 3, but accidentally shutting down a VM would mean data loss.
>>>
>>> We have quite a few VMs, but they all are used as real servers would be
>>> - all have different data (no scaleout) and none can be deleted easily.
>>>
>>
>> In OpenNebula 4.2 we included a new Sunstone cloud view [1] that fits in
>> your use case. You create base templates and create a set of images. Then a
>> user just have to select a template and an image, both are merged and a new
>> vm is created.
>>
>> You can also use this functionality in the default Sunstone view, but you
>> will have to enable it. If this the case just tell and will show you how.
>>
>> Concerning the persistence of the images, you have 2 options
>>   a) Persistent image: The information will be saved after a shutdown
>> action, but you can only use it in one vm
>>   b) Non persistent image: The information will be lost after a shutdown,
>> but you can use other actions that will not finalized the instance. For
>> example you can use the undeploy action [2] , it's like a shutdown but the
>> instance id, ip, disks.. are kept. You can deploy the vm again using the
>> resume action
>>
>>  Hope this helps
>>
>> [1] http://opennebula.org/documentation:rel4.2:cloud_view
>> [2]
>> http://opennebula.org/documentation:rel4.2:vm_guide_2#pausing_vm_instances
>>
>>
>>> --
>>>  Join us at OpenNebulaConf2013 <http://opennebulaconf.com/> in Berlin,
>>> 24-26 September, 2013
>>> --
>>> Daniel Molina
>>> Project Engineer
>>> OpenNebula - The Open Source Solution for Data Center Virtualization
>>> www.OpenNebula.org | dmolina at opennebula.org | @OpenNebula
>>>
>>>
>
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