Re: [Qemu-devel] [PATCH 1/1] NBD isn't used by qemu-img, so don't link qemu-img against NBD objects

[Kevin Wolf <kwolf@redhat.com>]

Am 22.11.2010 15:08, schrieb Jes Sorensen:
> On 11/22/10 13:24, Kevin Wolf wrote:
>> Am 19.11.2010 17:30, schrieb Jes.Sorensen@redhat.com:
>>> From: Jes Sorensen <Jes.Sorensen@redhat.com>
>>>
>>> Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
>>
>> You're compiling the nbd block driver out here. This is certainly not
>> what you were attempting. (However, it's the only way to make it work,
>> because otherwise qemu-img will need the top-level nbd.o)
>>
>> qemu-img -help before this change shows:
>>
>> Supported formats: raw cow qcow vdi vmdk cloop dmg bochs vpc vvfat qcow2
>> parallels nbd blkdebug sheepdog blkverify host_cdrom host_floppy
>> host_device file tftp ftps ftp https http
>>
>> Afterwards:
>>
>> Supported formats: raw cow qcow vdi vmdk cloop dmg bochs vpc vvfat qcow2
>> parallels blkdebug sheepdog blkverify host_cdrom host_floppy host_device
>> file tftp ftps ftp https http
> 
> I am aware of that, but what on earth is qemu-img doing with NBD in the
> first place? Doesn't make much sense to me.

The same as it's doing with file, host_device or http: Accessing images.
Start an NBD server (e.g. with qemu-nbd) and try something like qemu
-hda nbd:localhost. This is how you use the nbd block driver.

Kevin