Re: [PATCH v2 00/10] mirror: allow switching from background to active mode

[Vladimir Sementsov-Ogievskiy]

On 10.10.23 20:55, Vladimir Sementsov-Ogievskiy wrote:
> On 09.10.23 12:46, Fiona Ebner wrote:
> > Changes in v2:
> >      * move bitmap to filter which allows to avoid draining when
> >        changing the copy mode
> >      * add patch to determine copy_to_target only once
> >      * drop patches returning redundant information upon query
> >      * update QEMU version in QAPI
> >      * update indentation in QAPI
> >      * update indentation in QAPI (like in a937b6aa73 ("qapi: Reformat
> >        doc comments to conform to current conventions"))
> >      * add patch to adapt iotest output
> >
> > Discussion of v1:
> > https://lists.nongnu.org/archive/html/qemu-devel/2023-02/msg07216.html
> >
> > With active mode, the guest write speed is limited by the synchronous
> > writes to the mirror target. For this reason, management applications
> > might want to start out in background mode and only switch to active
> > mode later, when certain conditions are met. This series adds a
> > block-job-change QMP command to achieve that, as well as
> > job-type-specific information when querying block jobs, which
> > can be used to decide when the switch should happen.
> >
> > For now, only the direction background -> active is supported.
> >
> > The information added upon querying is whether the target is actively
> > synced, the total data sent, and the remaining dirty bytes.
> >
> > Initially, I tried to go for a more general 'job-change' command, but
> > I couldn't figure out a way to avoid mutual inclusion between
> > block-core.json and job.json.
>
> What is the problem with it? I still think that job-change would be better.

However, that's not a show-stopper. We have block-job-* commands, they are not 
deprecated, no problem to add one more.

--
Best regards,
Vladimir