Il 22/05/2013 17:51, Wolfgang Richter ha scritto: > On Thu, May 16, 2013 at 9:44 AM, Richard W.M. Jones <rjo...@redhat.com > <mailto:rjo...@redhat.com>> wrote: > > Ideally I'd like to issue some QMP commands which would set up the > point-in-time snapshot, and then connect to this snapshot over (eg) > NBD, then when I'm done, send some more QMP commands to tear down the > > snapshot. > > > This is actually interesting. Does the QEMU nbd server support multiple > readers?
Yes. > Essentially, if you're RWMJ (not me), and you're keeping a full > mirror, it's clear that the mirror write stream goes to an nbd server, > but is it possible to attach a reader to that same nbd server and read > things back (read-only)? Yes, it can be done with both qemu-nbd and the QEMU nbd server commands. Paolo