[Engine-devel] VM disks

[Livnat Peer]

On 19/02/12 12:35, Itamar Heim wrote:
> On 02/18/2012 07:07 PM, Livnat Peer wrote:
>> Hi,
>>
>> These days we are working on various features around VM disks, in the
>> different threads it was decided that we'll have the ability to attach a
>> disk to a VM but it will be added as inactive, then the user can
>> activate it for it to be accessible from within the guest.
>>
>> Flow of adding a new disk would be:
>> - creating the disk
>> - attaching the disk to the VM
>> - activating it
>>
>> Flow of adding a shared disk (or any other existing disk):
>> - attach the disk
>> - activate it
>>
>> It seems to me a lot like adding a storage domain and I remember a lot
>> of rejections on the storage domain flow (mostly about it being too
>> cumbersome).
> 
> true, you'll be asked to provide an option for the initial state in that
> case.
> 
>> After discussing the issue with various people we could not find a good
>> reason for having a VM disk in attached but inactive mode.
>>
>> Of course we can wrap the above steps in one step for specific flows
>> (add+attach within a VM context for example) but can anyone think on a
>> good reason to support attached but inactive disk?
>>
>> I would suggest that when attaching a disk to a VM it becomes part of
>> the VM (active) like in 'real' machines.
> 
> so hotunplug would make the disk floating, as it will detach it as well?

In short - yes.

The user will be able to attach/detach disk, the implementation would be
to hotplug or simply plug according to the VM status (up or not) .