On 20.11.19 16:58, Vladimir Sementsov-Ogievskiy wrote:
> 20.11.2019 18:18, Alberto Garcia wrote:
>> On Wed 20 Nov 2019 01:27:53 PM CET, Vladimir Semeeausntsov-Ogievskiy wrote:
>>
>>> 3. Also, the latter way is inconsistent with discard. Discarded
>>> regions returns zeroes, not clusters from
20.11.2019 19:46, Kevin Wolf wrote:
> Am 20.11.2019 um 16:58 hat Vladimir Sementsov-Ogievskiy geschrieben:
>> 20.11.2019 18:18, Alberto Garcia wrote:
>>> On Wed 20 Nov 2019 01:27:53 PM CET, Vladimir Semeeausntsov-Ogievskiy wrote:
>>>
3. Also, the latter way is inconsistent with discard.
Am 20.11.2019 um 16:58 hat Vladimir Sementsov-Ogievskiy geschrieben:
> 20.11.2019 18:18, Alberto Garcia wrote:
> > On Wed 20 Nov 2019 01:27:53 PM CET, Vladimir Semeeausntsov-Ogievskiy wrote:
> >
> >> 3. Also, the latter way is inconsistent with discard. Discarded
> >> regions returns zeroes, not
On Wed 20 Nov 2019 04:58:38 PM CET, Vladimir Sementsov-Ogievskiy wrote:
>> But then PREALLOC_MODE_OFF implies that the L2 metadata should be
>> preallocated (all clusters should be QCOW2_CLUSTER_ZERO_PLAIN), at
>> least when there is a backing file.
>
> Kevin proposed a fix that alters
20.11.2019 18:18, Alberto Garcia wrote:
> On Wed 20 Nov 2019 01:27:53 PM CET, Vladimir Semeeausntsov-Ogievskiy wrote:
>
>> 3. Also, the latter way is inconsistent with discard. Discarded
>> regions returns zeroes, not clusters from backing. I think discard and
>> truncate should behave in the
On Wed 20 Nov 2019 01:27:53 PM CET, Vladimir Semeeausntsov-Ogievskiy wrote:
> 3. Also, the latter way is inconsistent with discard. Discarded
> regions returns zeroes, not clusters from backing. I think discard and
> truncate should behave in the same safe zero way.
But then PREALLOC_MODE_OFF
20.11.2019 15:06, Alberto Garcia wrote:
> Hi,
>
> as we discussed yesterday on IRC there's an inconsistency in the way
> qcow2 preallocation works.
>
> Let's create an image and fill it with data:
>
> $ qemu-img create -f raw base.img 1M
> $ qemu-io -f raw -c 'write -P 0xFF 0 1M'
Hi,
as we discussed yesterday on IRC there's an inconsistency in the way
qcow2 preallocation works.
Let's create an image and fill it with data:
$ qemu-img create -f raw base.img 1M
$ qemu-io -f raw -c 'write -P 0xFF 0 1M' base.img
Now QEMU won't let us create a new image backed by
