[Engine-devel] multiple destinations for disks in create/import template?

[Itamar Heim]

On 02/02/2012 07:16 PM, Jon Choate wrote:
> On 02/02/2012 11:19 AM, Maor wrote:
>> On 02/02/2012 06:01 PM, Jon Choate wrote:
>>> Given the changes for multiple storage domains, do we want to allow a
>>> user to specify multiple storage domains per disk when creating or
>>> importing a template?
>>>
>>> Otherwise the user will need to use the copy(clone) template disk
>>> afterwards to create the copies of the storage domain disks where they
>>> want them.
>>>
>>> If so, what would the UI look for this? It would require the backend to
>>> receive something that looks like Map<DiskImage, List<StorageDomain>>.
>>>
>>> thoughts?
>> I think something that should be taken in consider if doing that, is
>> that the VM which the template is created from will stay in image lock
>> much longer.
> Not necessarily. Once we get one copy of each disk down, we can release
> the vm and use these copies as the source of the other copies.
>> Also what would be the desired behaviour if few of storage domains would
>> not be available, and will fail. (right now, if counting on the
>> AsyncTaskManager mechanism, the all operation of create template will be
>> rolled back, and the template would not be created at all.
> Yes, the failure cases need to be considered. I would think that as long
> as one copy of each disk can be created then the template should
> persist. If we can't create a copy of each disk then we need to roll
> back and not create the template.
>
> But in this approach how do we convey the list of failures back to the
> user?

how about we start with KISS to see everything works post all changes 
going around, and later can add support for multiple clones (parallel or 
serial)?