Re: [Qemu-devel] [PATCH] vmdk: improve streamOptimized vmdk support

[Stefan Hajnoczi]

On Tue, Jul 29, 2014 at 3:49 PM, Milos Vyletel <address@hidden> wrote:
> On Tue, Jul 29, 2014 at 10:37 AM, Stefan Hajnoczi <address@hidden> wrote:
>> On Tue, Jul 29, 2014 at 2:46 PM, Milos Vyletel <address@hidden> wrote:
>>> On Tue, Jul 29, 2014 at 9:37 AM, Stefan Hajnoczi <address@hidden> wrote:
>>>> On Mon, Jul 07, 2014 at 10:54:27AM -0400, Milos Vyletel wrote:
>>>>> VMDK's streamOptimized format is different that regular sparse format.
>>>>> L1(GD) and L2(GT) tables are not predefined but rather generated and
>>>>> written during image creation mainly because there is no way to tell
>>>>> how much space data will occupy once they are compressed. Also the
>>>>> location of header, L1 and L2 tables differs.
>>>>>
>>>>> - L2 tables (grain tables) are written after all grains they point to
>>>>> - L1 tables are written after all grains and L2 tables
>>>>> - footer at the end is used instead of header in first sector
>>>>>
>>>>> This patch improves streamOptimized support and adds possibility to
>>>>> create true streamOptimized images using qemu-img. Some of the changes
>>>>> are from VMDK specs, some of them from hexdump-ing images from VMWare
>>>>> and VirtualBox.
>>>>>
>>>>> I have compared these images to the ones generated by VMWare and vbox
>>>>> and they are identical with the exception of DescriptorFile that has
>>>>> some differences but none that would change behavior(CID and some
>>>>> additional DDB entries differ) and streamOptimized image generated from
>>>>> raw image was succesfully imported (as OVA) into VMWare ESXi and Oracle
>>>>> OVM.
>>>>>
>>>>> Signed-off-by: Milos Vyletel <address@hidden>
>>>>> ---
>>>>>  block/vmdk.c |  363 
>>>>> +++++++++++++++++++++++++++++++++++++++++++++-------------
>>>>>  1 files changed, 281 insertions(+), 82 deletions(-)
>>>>
>>>> What does this patch do beyond what QEMU already supports today?
>>>>
>>>> Is there a particular application that rejected QEMU's streamOptimized
>>>> images?  Is this a bug fix?
>>>>
>>>> Please use scripts/checkpatch.pl to check coding style.
>>>>
>>>> Fam: Please review
>>>>
>>>
>>> Images created/converted using QEMU were rejected by VMWare ESXi,
>>> vCloud, VirtualBox and Oracle OVM. I did not try anything else.
>>>
>>> Generally speaking streamOptimized format is not followed by QEMU.
>>> Instead regular VMDK format + encryption is used. We can say this is
>>> bug fix since streamOptimzed format is already included but does not
>>> work well.
>>>
>>> I'll check the style and fix the code. I'll postpone resubmit until
>>> further review is done since I'm sure there will be things that will
>>> need to be fixed.
>>
>> What was the command-line you used?
>>
>> qemu-img convert -f qcow2 -O vmdk -o subformat=streamOptimized
>> input.qcow2 output.vmdk
>>
>> Stefan
>
> I've been using test image from
> http://wiki.qemu.org/download/linux-0.2.img.bz2 and converting it like
> this:
>
> qemu-img convert -O vmdk -o
> adapter_type=lsilogic,compat6,subformat=streamOptimized linux-0.2.img
> linux-0.2.vmdk

Okay, great.  I wanted to check that you used subformat=streamOptimized.

If possible, please be more specific in the commit description about
what caused ESXi and other software to reject the image and what
exactly this patch changes.

Stefan