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. Thanks Wen Congyang > > Kevin/Stefan, is there a design document somewhere that covers at least > static filters? > > Paolo > . >
