[dm-devel] Multipath on STK OPENStorage D240

[Philip R. Auld]

Hi,

Rumor has it that on Thu, May 04, 2006 at 09:41:20AM +0200 Guido Guenther said:
> Hi,
> when using path_checker readsector0 on the above machine the box stalls
> every 5 seconds when checking the currently nonactive path. Same for
> path_checker tur. Is there a way to avoid this? I'd consider writing a
> specific checker but am lacking any documentation.

This thing is a preferred path array. I can see how readsector0
is probably the wrong choice of checker. I imagine it causes 
a cache flush from the preferred controller. Odd that the tur
checker has the same behavior. If you want to code something 
you might try a checker that just does a standard INQUIRY.
I'd think that would not cause a cache flush, but then
I'd have thought that about the TUR as well... Such a checker 
may be useful for other preferred path arrays. 

I've got an STK array here but haven't gotten access to it 
yet to run dm-multipath so I can't confirm having seen this
problem.


Cheers,

Phil


> Cheers,
>  -- Guido
> 
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-- 
Philip R. Auld, Ph.D.  	        	       Egenera, Inc.    
Software Architect                            165 Forest St.
(508) 858-2628                            Marlboro, MA 01752