Re: [Qemu-devel] [patch 2/3] Add support for live block copy

[Anthony Liguori]

On 02/25/2011 06:02 PM, Marcelo Tosatti wrote:
> > > +- "commit_filename": target commit filename (json-string, optional)
> > >        
> > I think we should drop this.
> >      
> Why? Sorry but this can't wait for non-config persistent storage. This
> mistake was made in the past with irqchip for example, lets not repeat
> it.
>
> Its OK to deprecate "commit_filename" in favour of its location in
> non-config persistent storage.
>
> Its not the end of the world for a mgmt app to handle change (not saying
> its not a good principle) such as this

If you're looking for a stop-gap, I'd suggest adding an optional 
"action" parameter.  This parameter would take a string with valid 
values of "stop", "none".

If action=stop, then when block copy finishes, the guest will be stopped 
and an event will be sent.  This lets a management tool get notified, 
update it's config, and then continue the guest.  If the management tool 
crashes, it can do a query-block-copy to see that the copy finished 
along with a query-status to fix the guest.

This is more in line with how our other commands work.

Regards,

Anthony Liguori