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Subject: Re: [Qemu-devel] [RFC PATCH] replication agent module
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org

On 02/07/2012 04:05 PM, Paolo Bonzini wrote:
> On 02/07/2012 02:50 PM, Stefan Hajnoczi wrote:
>>> I guess we might need to attach multiple QMP monitors for this to work
>>> (one for libvirt, one for the rephub). I'm not sure if there is a
>>> fundamental problem with this or if it just needs to be done.
>>
>> Agreed.  You can already query block devices using QMP 'query-block'.
>> By adding in-process NBD server support you could then launch an NBD
>> server for each volume which you wish to replicate.  However, in this
>> case it sounds almost like you want the reverse - you could provide an
>> NBD server on the rephub and QEMU would mirror writes to it (the NBD
>> client code is already in QEMU).
> 
> Yes, this is how we were also planning to do migration without shared storage, right?

We originally planned to run ISCSI target . But now that NBD can handle a file chain we can use it too.

> 
> Paolo
> 
>