Re: [Qemu-devel] Re: KVM call minutes for June 8

[Kevin Wolf]

Am 09.06.2010 18:22, schrieb Anthony Liguori:
> On 06/09/2010 10:31 AM, Daniel P. Berrange wrote:
>>>   However, libvirt was counting on this feature and on the snapshot commands
>>> to switch from the text Monitor. We have two options:
>>>
>>>   1. Ask them to wait one more release (not so good for us)
>>>   2. Try to find a way to have those features in for 0.13
>>>
>>>   Daniel has commented to me that making the snapshot commands synchronous
>>> for 0.13 wouldn't be that bad, what do you think?
>>>      
>> The thought is that changing a command from synchronous to asynchronous is
>> not an ABI incompatible change. An existing app simply won't know to take
>> advantage of the new possibilities that async commands offer.
>>    
> 
> It's not QMP that's the major issue with savevm.  The major issue is 
> actually the way snapshots are saved in qcow2.  You need to know the 
> size of the snapshot prior to creating the snapshot

Huh, why this? Seems I still haven't understood all of qcow2 then... I
always thought that there's just a specific offset where VM state
starts, but no explicit end.

Kevin