* Wen Congyang (we...@cn.fujitsu.com) wrote: > On 04/24/2015 03:47 PM, Paolo Bonzini wrote: > > > > > > On 24/04/2015 04:16, Wen Congyang wrote: > >>>>>> I think the primary shouldn't do any I/O after failover (and the > >>>>>> secondary should close the NBD server) so it is probably okay to ignore > >>>>>> the removal for now. Inserting the filter dynamically is probably > >>>>>> needed though. > >>>> > >>>> Or maybe just enabling/disabling? > >> Hmm, after failover, the secondary qemu should become primary qemu, but we > >> don't > >> know the nbd server's IP/port when we execute the secondary qemu. So we > >> need > >> to inserting nbd client dynamically after failover. > > > > True, but secondary->primary switch is already not supported in v3. > > Yes, we should consider it, and support it more easily later. > > If we can add a filter dynamically, we can add a filter that's file is nbd > dynamically after secondary qemu's nbd server is ready. In this case, I think > there is no need to touch nbd client.
Yes, I think maybe the harder part is getting a copy of the current disk contents to the new secondary while the new primary is still running. Dave > > Thanks > Wen Congyang > > > > > Kevin/Stefan, is there a design document somewhere that covers at least > > static filters? > > > > Paolo > > . > > > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
