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On 11/27/2012 11:38 AM, Christoph Hellwig wrote:
> On Tue, Nov 27, 2012 at 08:12:59AM -0800, Vishvananda Ishaya wrote:
>> for this. It seems like the fastest path to using LIO would be to simply
>> extend the tgt code to be able to use targetcli[1] in addition to tgtadmin
>> and ietadmin. That seems like literally a few days of work.
>>
>> Integrating targetd sounds more complicated and I think it would be better
>> done with its own driver. If you are managing volumes remotely I don't think you
>> are going to get much benefit out of sharing the existing target code.
>>
>> Would you consider a dual approach? A quick-and-dirty version using targetcli
>> to get lio support in, followed by a more general driver using targetd?
> 
> I think the "simple" driver using targetcli would fit the current cinder
> model fairly well.  It would essentially just plug another class into
> the abstraction between TgtAdm and IetAdm provided by
> get_target_admin().

IIRC, targetcli doesn't provide any usable way to detect errors (return
codes or pareseable output).  If I'm wrong, or if we can help improve
that, that sounds ok to me.

> The way I understand targetd (and Andy may have to correct me) it
> actually managed the backend storage using e.g. LVM as well.

Agreed that it seems to make more sense for targetd to be its own Cinder
driver.

-- 
Russell Bryant