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

[Milos Vyletel]

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

Milos