[Libguestfs] [PATCH virt-v2v] v2v: -o rhv-upload: Enable multi-conn

[Richard W.M. Jones]

On Tue, Aug 03, 2021 at 10:36:47PM +0300, Nir Soffer wrote:
> On Tue, Aug 3, 2021 at 10:26 PM Eric Blake <eblake at redhat.com> wrote:
> >
> > On Mon, Aug 02, 2021 at 08:41:20AM +0100, Richard W.M. Jones wrote:
> > > ---
> > >  v2v/rhv-upload-plugin.py | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > >
> > > diff --git a/v2v/rhv-upload-plugin.py b/v2v/rhv-upload-plugin.py
> > > index a3d578176..51e9b33f7 100644
> > > --- a/v2v/rhv-upload-plugin.py
> > > +++ b/v2v/rhv-upload-plugin.py
> > > @@ -169,6 +169,10 @@ def open(readonly):
> > >      }
> > >
> > >
> > > +def can_multi_conn(h):
> > > +    return True
> >
> > Should this be h['can_flush'] instead of True?
> >
> > Are we guaranteed that imageio guarantees a consistent image across
> > all other http connections when a flush is received on a single http
> > connection?
> 
> imageio keeps multiple connections to qemu-nbd, and pass all requests
> to qemu-nbd. No caching is done in imageio.
> 
> But we don't do any synchronization, so we may have one flush command
> in the middle of a write/write_zeros commands.
> 
> Does qemu-nbd wait until the write/wirte_zeros commands complete
> before flushing?

I should note that virt-v2v (the only place this plugin is used) is a
special case because we control the NBD client and we're only doing a copy.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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