Re: [Qemu-block] [Qemu-devel] storing machine data in qcow images?

[Eduardo Habkost]

On Wed, Jun 06, 2018 at 02:50:10PM +0100, Daniel P. Berrangé wrote:
> On Wed, Jun 06, 2018 at 03:45:10PM +0200, Michal Suchánek wrote:
> > 
> > I think that *if* we want an 'appliance' format that stores a whole VM
> > in a single file to ease VM distribution then the logical place to look
> > in qemu is qcow. The reason have been explained at length.
> 
> I rather disagree. This is a common problem beyond just QEMU and everyone
> just uses an existing archive format (TAR, ZIP) for bundling together
> one or more disk images, metdata for config, and whatever other resources
> are applicable for the vendor.  This works with any disk format (raw,
> qcow2, vmdk, vpc, etc) so is preferrable to inventing someting that is
> specific to qcow2 IMHO.

Now we have N+1 appliance file formats.  :)

(We like it or not, qcow2 is already used as an appliance format
for single-disk VMs in practice.)

But I agree this must not be specific to qcow2.  The same VM
description format we agree upon should work with other disk
formats or with multi-disk appliances.

If we specify a reasonable VM description format for appliances
and make it work inside (e.g.) tar files, we will still have the
option of allowing the description be placed inside qcow2 if we
really want to.  I don't think we need to finish this qcow2
bikeshedding exercise right now.

-- 
Eduardo