openstack team mailing list archive

[Caitlin Bestler <Caitlin.Bestler@xxxxxxxxxxx>]

Andi Abes wrote:


> On Wed, Apr 25, 2012 at 3:39 PM, Caitlin Bestler <Caitlin.Bestler@xxxxxxxxxxx> wrote:
>> andi.abes asked:
>>
>>> Would this also be applicable to the ephemeral instance storage?
>>
> >An ephemeral instance is essentially a non-persistent clone of a snapshot image.
>>
>that's an interesting perspective. But currently, those can be snapshotted and made into new images (see [1]).
>The approach you're describing appears to depend heavily on capabilities of backend storage devices.
> If snapshoting is only supported using these capabilities - would it mean deprecating these capabilities? (or did you just not consider them?)

Given that Nexenta makes an appliance that acts as a backend storage device, my having that perspective is not surprising.

However, I think it is reasonable to expect that pseudo-device like qcow emulate the capabilities of the actual backend storage services.
The definitions that are the consensus of the backend storage device vendors already encompass a variety of implementations, which
the pseudo-devices could easily implement in software.