Re: [libvirt] [Qemu-devel] live snapshot wiki updated

> > Right, we're stuck with the two horros of NFS and selinux, so we need > > something that gets around the problem. In a sane world we would simply > > say 'no NFS, no selinux', but as you say that will never happen. > > > > My suggestion of a callback mechanism where libvirt registers the > > callback with QEMU for open() calls, allowing libvirt to perform the > > open and return the open file descriptor would get around this problem. To me this sounds more like a problem than a solution. It basically means that during an open (which may even be initiated by a monitor command), you need monitor interaction. It basically means that open becomes asynchronous, and requires clients to deal with that, which sounds at least "interesting"... Also you have to add some magic to all places opening something. I think if libvirt wants qemu to use an fd instead of a file name, it shouldn't pass a file name but an fd in the first place. Which means that the two that we need are support for an fd: protocol (patches on the list, need review), and a way for libvirt to override the backing file of an image.