Re: [Qemu-devel] [Bug 826363] Re: qemu-img convert does not work with vdi files

[Stefan Weil <weil@mail.berlios.de>]

Am 20.08.2011 10:50, schrieb Stefan Weil:
> Am 17.08.2011 18:44, schrieb Stefan Hajnoczi:
>> On Wed, Aug 17, 2011 at 5:29 PM, Stefan Hajnoczi <stefanha@gmail.com> 
>> wrote:
>>> On Tue, Aug 16, 2011 at 7:07 PM, Steve Si 
>>> <826363@bugs.launchpad.net> wrote:
>>>> I got binaries from http://homepage3.nifty.com/takeda-toshiya/
>>>>
>>>> tested under Win 7 64-bit as User=Administrator
>>>>
>>>> qemu10.6 - works  makes      16/08/2011  18:43     3,096,481,792 
>>>> test.raw
>>>> qemu11.1 - works  makes      16/08/2011  18:43     3,096,481,792 
>>>> test.raw
>>>> qemu12.1 - crashes !
>>>> qemu12.2 - crashes !
>>>> qemu12.5 - error while writing
>>>
>>> I think this crash->error transition is explained by:
>>>
>>> commit 8cef921d18025b4ce4e749eed391308033fee232
>>> Author: TeLeMan <geleman@gmail.com>
>>> Date:   Mon Feb 8 16:20:00 2010 +0800
>>>
>>>    qemu-img: use the heap instead of the huge stack array for win32
>>>
>>> But we still don't know why you are getting the write error.  It would
>>> be fairly easy to find that out by building QEMU from source and
>>> adding fprintf() where the write fails - print out the error code and
>>> sector number.
>
> The current code only supports images (any format) with less than
> 4 GiB (maybe even less than 2 GiB).
>
> This limitation is caused by the usage of function ftruncate to create
> the destination file. ftruncate takes a long (32 bit) parameter.

I did not notice that ftruncate is mapped to qemu_ftruncate64, so my
analysis was not correct. The implementation of qemu_ftruncate64
was buggy. It's fixed now, and working binaries are available from
http://qemu.weilnetz.de/w32/2011-08-20/.