Re: [Qemu-devel] [PATCH] Warn if a qcow (not qcow2) file is opened

[Kevin Wolf]

Anthony Liguori schrieb:
> Kevin Wolf wrote:
>> Avi Kivity schrieb:
>>   
>>> The qcow block driver format is no longer maintained and likely contains
>>> serious data corruptors.  Urge users to stay away for it, and advertise
>>> the new and improved replacement.
>>>
>>> Signed-off-by: Avi Kivity <address@hidden>
>>>     
>> vvfat is using qcow internally, so the warning will appear there, too.
>> Not that warning against vvfat would be a bad thing, but this error
>> message could be confusing.
>>
>> Maybe we're lucky enough and vvfat survives a s/qcow/qcow2/, but I
>> really never wanted to touch that code...
>>   
> 
> I'm not sure how I feel about this.  Can we prove qcow is broken?  Is it 
> only broken for writes and not reads?
> 
> If we're printing a warning, does that mean we want to deprecate qcow 
> and eventually remove it (or remove write support, at least)?

I haven't commented on the intention of deprecating qcow1, I'm not sure
either. But the bug that turned up yesterday was present for a month and
nobody saw it. So I guess we can take that as a sign that qcow isn't
really used that much any more.

On the other hand, I think maintaining qcow1 isn't that hard. It won't
get new features, so we'll not have a whole lot of changes. We must test
it from time to time. And when it comes to fixing, I think qcow1 is much
easier for us than, say, VMDK.

Kevin