Il 31/07/2012 11:26, Kevin Wolf ha scritto: > Am 24.07.2012 13:04, schrieb Paolo Bonzini: >> This adds the monitor commands that start the mirroring job. >> >> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > > [ Moving the discussion upstream ] > >> Why make all of it inaccessible? Everything except target device access >> does have a stable API. The target device access can be delayed to 1.3, >> together with the much-needed QMP schema introspection. > > I'm not even sure about the QMP mirror command itself. > > I don't really like it, it does too many things at once: It can create > the target image file, it opens the target and it actually starts the > mirroring. It's rather bad at the first two steps, because it doesn't > take any options. This means that it can't create qcow2v3 images, for > example. Or you can't mirror into a backup with cache=unsafe while > running your real VM on cache=writethrough.
Yes, though this can be worked around with mode: 'existing'. > Having an all-in-one mirror command is a nice feature for HMP, but for > QMP it's more like a design problem. > > Now I see you have called it drive-mirror I thought this was your idea. :) > , so that kind of implies that > it's not the final blockdev-mirror but just a QMP version of a command > primarily designed for HMP. As such this restricted functionality may be > acceptable, but it's not like everything is already perfect and there's > no room for discussion. We keep going back to the same point that we do not have -blockdev, but it's becoming a bit frustrating to always rehash this same point... Paolo
