CRN

[Binford, Charles]

* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* "Binford, Charles" <charles.binford at symbios.com>
*
See below...

Charles Binford
Symbios Inc.
316-636-8566

> -----Original Message-----
> From:	Dave Peterson [SMTP:dap at nsco.network.com]
> Sent:	Thursday, June 25, 1998 5:10 PM
> To:	FC at nsco.network.com
> Cc:	t10 at symbios.com
> Subject:	Re: CRN
> 
> Dal Allan wrote: 
> 
> 	Hi Doug, 
> 
> 	> If there is no CRN associated with task management functions,
> then how 
> 	> do you know if one gets lost? 
> 
> 	You won't if you queue them, but nobody in their right mind
> would do that, 
> 	task management have to be interlocked so they can be
> controlled. 
> 
> 	It was Matt who asked the right question in the meeting. 
> 
> 	"If the task management function has a CRN and the target is not
> accepting 
> 	Sequences because there is an out-of-order problem how are you
> going to get 
> 	the task management Sequence accepted by the target?" 
> 
> 	Dal
> 
> Shouldn't the question read: 
> 
> "If the task management function has a CRN and the target is not
> accepting 
> Exchanges because there is an out-of-order problem how are you going
> to get 
> the task management Exchange accepted by the target?" 
	[cb]  I agree.  We are talking Exchange, not sequence.  I'm sure
that's what Dal meant :-)

> And the answer: 
> Assuming an in-order environment retransmit the required
> command/CRN(s).
	[cb]  I don't get it.  At this point I'm not wanting to
retransmit the command, I'm wanting to abort a set of IOs or tell the
target to reset himself because I think he is confused.   If part of the
target's confusion deals with managing the CRN number and the task
management function has to have a "valid" CRN to be accepted then it
seems I (the host) am stuck with a guessing game.  Not having a CRN on
the task management funcitons seems to simplify things.
>  
> If the command/CRN cannot be sent successfully within the ULP timeout
> chances 
> are the loop is not well. PRLO will clear the tasks, PRLI will clear
> the CRN. 
> -- 
> ===================================================================
> Dave Peterson                     phone : 612-391-1008
> Senior Engineer 
> StorageTek Network Systems Group  email: dap at network.com
>  
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