Re: [Qemu-devel] [PATCH v4 0/6] Efficient VM backup for qemu

[Paolo Bonzini]

Il 22/02/2013 18:57, Dietmar Maurer ha scritto:
>>> If we use nbd, how can we pass additional information to the other
>>> side, for example information about unallocated regions?
>>>
>>
>> You can either send trim commands, or just skip those regions and let the 
>> other
>> side figure it out.
> 
> But we are lost if we want to transfer something else? I am currently not 
> sure what we
> want to transfer, but I am sure we will find something in future.
> 
> Or can we simply add a header to each write with additional information? 

Let's discuss it once we have a clearer picture of what that additional
info would be.

Paolo