Hannes Reinecke wrote:
[ .. ]
> However: The main reason why we're getting flooded with MODE SELECT 
> commands
> is that the RDAC handler switches _each LUN_, not the entire controller.
> Seeing that the controller simply cannot cope with the resulting MODE 
> SELECT
> flood wouldn't it be more sensible to switch the entire controller here?
> 
> After all, we're trying to address a communication failure between the
> HBA and the controller, not a failure between the controller and the LUN.
> And by that reasoning switching individual LUNs is quite pointless as we
> have to switch _all_ LUNs handled by this controller eventually.
> 
> So I would suggest to first issue a MODE SENSE command to check which LUNs
> are currently handled by this controller and then switch those LUNs in
> one go. This way we would be sending quite a few MODE SENSE commands,
> but I was under the impression that those do not have any restriction.
> 
> I will see to draw up a patch.
> 
Was easier than I thought. Patch is attached.
Note: Proof of concept only. No warranties.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
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