P1394> Dynamic LUNs

P1394> Dynamic LUNs

Turner, Randy rturner at sharplabs.com
Tue May 26 13:32:09 EDT 1998


This LUN 0 allocation would only affect us if a Win98/NT5.0 host was the
"target" in a particular config...I didn't think the Microsoft driver
would interfere with us trying to access any arbitrary LUN on "another"
node...(?)


Randy




	-----Original Message-----
	From:	Greg Shue [SMTP:gregs at sdd.hp.com]
	Sent:	Tuesday, May 26, 1998 9:37 AM
	To:	rturner at sharplabs.com
	Cc:	p1394 at pwg.org
	Subject:	Re: P1394> Dynamic LUNs




	SBP-2 says that LUN zero must exist.


	When PWG representatives went to Redmond, Microsoft said that
	their driver only supports LUN zero.  They also said that LUN
	zero needs to be directly mapped to a higher layer, because they
	won't support dynamic LUNs.


	So, we should think of LUN zero as being "allocated".


	NOTE:  Someone (Brian?)  in VA.  said that Microsoft's driver
	will be extended to support more LUNs.  There was a comment made
	(from the Microsoft rep?)  that Microsoft still will not support
	dynamic LUNs.


	> 
	> 
	> I'm not sure what you are recommending in comment (B) below.
If this came
	> up at the Virginia meeting, can someone elaborate as if LUN 0
for a
	> particular unit has been "allocated" by Microsoft or some
other group?
	> 
	> Randy
	> 
	> 
	> 
	> At 05:03 PM 5/14/98 -0700, Greg Shue wrote:
	> >
	> >Here's some comments on the Dynamic LUN notes sent out by
Alan.
	> >
	> >A)  I don't think the Dynamic Logical Unit Number scheme was
	> >    intended to _multiplex_ applications to device functions.
	> >    I think it is intended on providing the ability for a
node
	> >    to establish a unique connection to identical instances
of
	> >    a service without having to:
	> >
	> >      1-  Assign fixed LUNs for each service instance
	> >      2-  Crowd the Config ROM with redundant information
	> >
	> >B)  After discussions with folks from Microsoft, I would
strongly
	> >    recommend NOT using LUN 0 (zero) for anything but a
direct
	> >    connection to an instance of the transport client.  The
LUN-server
	> >    could easily be identified in the Config ROM as belonging
to
	> >    a different LUN.  (Since it's really a different service
	> >    than the transport client.)
	> >
	> >C)  The SBP-2 initiator and target drivers do not change a
bit.
	> >    Reconnect proceeds normally.  The initiator and target
SBP-2
	> >    drivers must already remember LUNs, EUI-64 values, and
LoginIDs.
	> >
	> >D)  The SBP-2 driver probably will already map connections
(LoginIDs?)
	> >    to a socket ID or some other appropriate OS mechanism.
	> >
	> >It still strikes me as a clean, simple way to get beyond the
constraints
	> >of SBP-2 when appropriate.  Best of all, it's optional!
	> >
	> >-- 
	> >Greg Shue
	> >Hewlett-Packard Company
	> >Office Products Division			gregs at sdd.hp.com
	>
>----------------------------------------------------------------
	> > 
	> 
	> 




	-- 
	Greg Shue
	Hewlett-Packard Company
	Office Products Division			gregs at sdd.hp.com
	----------------------------------------------------------------



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