[Libvir] Supporting new Xen 3.0.3 blktap backend for file devices

Karel Zak kzak at redhat.com
Wed Sep 27 17:05:38 UTC 2006


On Tue, Sep 26, 2006 at 08:08:33PM +0100, Daniel P. Berrange wrote:
> 
> This means the easy option of just making all file devices use blktap in
> 3.0.3 is not practical. This in turns means we need to  come up with a
> way to express the new driver methods in libvirt XML. There are a few
> options I can think of :
> 
>  - Allow more values in the 'type' attribute, eg file, block, blktap:aio,
>    blktap:qcow, etc. This feels wrong because the blktap:* entries are
>    really still 'file' types.
> 
>  - Introduce a new attribute  'driver'  where you can specify 'loop',
>    'blktap:aio', 'blktap:qcow', etc
> 
>  - Introduce a new element 'driver' where you can specify the same
> 
>        <disk type="file">
>           <driver type='blktap:aio'/>
>        </disk>
> 
>  - Same as above, but normalize the driver type further
> 
>        <disk type="file">
>          <driver type='blktap' backend='aio' />
>        </disk>
> 
> My preference is probably option 3 or 4.

 My preference is definitely 4.
 
 (well, I'm affected by Database Normalization where it's bad merge
 two information into one attribute -- so 'blktap:aio' is wrong way
 ;-)

    Karel

-- 
 Karel Zak  <kzak at redhat.com>




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