On 2018-05-28 20:38, Kevin Wolf wrote:
> Am 28.05.2018 um 20:30 hat Richard W.M. Jones geschrieben:
>> On Mon, May 28, 2018 at 08:10:32PM +0200, Max Reitz wrote:
>>> As someone who is just naive and doesn't see the big picture, I don't
>>> see what's wrong with using a tar file that contains the image and
>>> additional data.
>>
>> FWIW an OVA file is exactly this: an uncompressed tar file containing
>> disk image(s) and metadata.
> 
> If we combine VM configuration and the disk image this way, I would
> still want to directly use that combined thing without having to extract
> its components first.
> 
> Just accessing the image file within a tar archive is possible and we
> could write a block driver for that (I actually think we should do
> this), but it restricts you because certain operations like resizing
> aren't really possible in tar. Unfortunately, resizing is a really
> common operation for non-raw image formats.
> 
> And if I think of a file format that can contain several different
> things that can be individually resized etc., I end up with qcow2 in the
> simple case or a full file system in the more complex case.

Well, you end up with VMDK.

Max