Il 23/04/2013 20:31, Wolfgang Richter ha scritto: > On Tue, Apr 23, 2013 at 2:21 PM, Stefan Hajnoczi <stefa...@gmail.com > <mailto:stefa...@gmail.com>> wrote: > > The tracing subsystem is geared towards tracepoint instrumentation > rather than binary dumps. > > Can you share some specific applications? > > > Well, my main application is in exposing a "cloud-inotify" service by > interpreting > sector writes in real-time and publishing the updates as file system > manipulations. > By using introspection we don't need agents running inside the guest. > > Example: guest writes to sector 5786907; I reverse-map that sector and > notice > it belongs to '/etc/passwd' within that guest; I immediately emit a message > (currently using Redis pub-sub functionality) to any interested > subscribers that > '/etc/passwd' changed within this guest running on a certain host within the > datacenter.
If you are okay with writes being "bundled" and you are able to handle reordered writes within a small timeframe (usually 0.1-1s), then you can use drive-mirror with an NBD destination. Paolo
