RE: iSCSI : login keys & mode page settings

[julian_satran@il.ibm.com]

Black_David@emc.com on 20/04/2001 19:12:04

Please respond to Black_David@emc.com

To:   Julian Satran/Haifa/IBM@IBMIL, ips@ece.cmu.edu
cc:
Subject:  RE: iSCSI : login keys & mode page settings




Without getting into the technical details of the
discussion, I have a couple of observations:

(A) The issue of whether to allow mode page
     access to and modification of iSCSI parameters
     will need to be taken up at the interim
     meeting.  IMHO, access seems like a good
     idea, so that SCSI-generic code that doesn't
     know specifically about iSCSI can find
     what it expects where it expects it, but
     I'm unsure about modification because it
     may carry a risk of code that's iSCSI-unaware
     getting something wrong.  The mode page
     commands should be transparent to iSCSI.

+++ I would like to point out that there are three mode pages that have
parameters that are either completely protocol specific (LU & Port) or with
semantics that are protocol specific(disconnect/reconnect). Code that is
completely iSCSI unaware must not touch protocol specific parameters.

The setting is is more delicate issue and our solution just bring the
"negotiation" into modern age.  It is not radically better but it gives
some uniformity to iSCSI driver and target logic.

I would have suggested removing mode set access for those parameters but
this is hard to enforce in a port/miniport of high-level/low-level code
structure.  :-)

+++

(B) The mode page and text key mechanisms have
     to access the same data.  Section 3 of the
     -06 version says this, but needs some editing
     to enforce it by using "MUST" or its equivalent
     (cf. RFC 2119).  This is to prevent an
     implementation from having two instances of
     the same parameter - one for the mode page and
     one for the text keys - which would be a bad
     thing.
+++ I will try to - although boldface is forbiden in text-only :-) +++
--David

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