Re: [Qemu-devel] Image streaming and live block copy

[Stefan Hajnoczi <stefanha@gmail.com>]

On Fri, Jun 17, 2011 at 10:22 AM, Kevin Wolf <kwolf@redhat.com> wrote:
> Am 17.06.2011 10:57, schrieb Stefan Hajnoczi:
>> On Fri, Jun 17, 2011 at 9:36 AM, Kevin Wolf <kwolf@redhat.com> wrote:
>>> By the way, we'll get problems with the colon syntax. Without -blockdev
>>> we'll have to invent a new syntax, maybe with brackets:
>>>
>>> blkstream:[nbd:localhost]:out.qcow2
>>
>> Embedding block driver options in filenames is getting worse as time
>> goes on.
>
> Well, yes. We need -blockdev for a sane way to express complex relations
> between BlockDriverStates. But then, we'll also want to have convenient
> shortcuts for manual use, and that may be something like the existing
> colon syntax. I really don't feel like typing three full -blockdev
> parameters for qcow2 on blockdbg on raw.
>
>> I recently tried to refactor and eliminate
>> QEMUOptionParameter so that we only use QemuOpts instead of two
>> different option APIs.  Part of that involves keeping separate
>> per-block driver (i.e. -blockdev) options lists, which would allow us
>> to pass proper options to block drivers instead of embedding them in
>> the filename.
>
> Aren't these completely independent things? QEMUOptionParameter is used
> for image creation, whereas filenames are used for opening images. I
> think you can change one without changing the other.

Yeah but I'd rather not spread two different APIs to do the same
thing.  Most of QEMU uses QemuOpts but image creation uses
QEMUOptionParameter.  The longer we leave that the more quirks like
the concatenation behavior will fragment the two.

Stefan