Re: [Qemu-devel] Block format 'raw' does not support the option 'share-rw'

Re: [Qemu-devel] Block format 'raw' does not support the option 'share-rw'

[Kevin Wolf]

Am 28.03.2019 um 21:48 hat Michal Suchánek geschrieben:
> On Thu, 28 Mar 2019 16:56:48 +0100
> Michal Suchánek <msuchanek@suse.de> wrote:
> 
> > Hello,
> > 
> > I tried to update my machine definitions to work with current qemu.
> > 
> > Unfortunately, while qemu 2.11 supports disk sharing with raw images
> > qemu 3.1 does not. That looks bogus to me. What is not supported about
> > writing random block into a file in parallel?
> 
> And of course it is because the option is supported on a different
> option (yes, options that have options get convoluted) and the error
> message is quite unhelpful in diagnosing that.
> 
> Now if different formats can register new option handlers which
> magically make an option supported I don't see how the diagnostic can
> do much better, unfortunately.

That's not really what happens. This is an option of the virtual device,
not of the format driver. The format driver is not involved at all,
which is why it's just an unknown option for it.

Kevin