Re: [storm] iSCSI feature removal: SLP ?

"Mark S. Edwards" <marke@muttsnuts.com> Wed, 23 June 2010 22:23 UTC

Return-Path: <marke@muttsnuts.com>
X-Original-To: storm@core3.amsl.com
Delivered-To: storm@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 866743A6801 for <storm@core3.amsl.com>; Wed, 23 Jun 2010 15:23:15 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 0.002
X-Spam-Level:
X-Spam-Status: No, score=0.002 tagged_above=-999 required=5 tests=[AWL=-0.001, BAYES_50=0.001, UNPARSEABLE_RELAY=0.001]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5K+PYFQWqAi1 for <storm@core3.amsl.com>; Wed, 23 Jun 2010 15:23:11 -0700 (PDT)
Received: from smtp112.biz.mail.mud.yahoo.com (smtp112.biz.mail.mud.yahoo.com [209.191.68.77]) by core3.amsl.com (Postfix) with SMTP id 1F1AD3A687E for <storm@ietf.org>; Wed, 23 Jun 2010 15:23:11 -0700 (PDT)
Received: (qmail 77618 invoked from network); 23 Jun 2010 22:23:16 -0000
Message-ID: <654733.53196.qm@smtp112.biz.mail.mud.yahoo.com>
Received: from Lipwig.muttsnuts.com (marke@86.180.99.4 with login) by smtp112.biz.mail.mud.yahoo.com with SMTP; 23 Jun 2010 15:23:16 -0700 PDT
X-Yahoo-SMTP: bRG7rdWswBCH1dgXoodv3R.kBjic
X-YMail-OSG: DVO11D8VM1ms8z9Osa7waGuIPbvYh9OAJWTYRE3Wt3PsapO UlWzNAyagd3WuwjiKXQY370.foI9GUXpoGly.MopypNv02TLD4m0VypMxFOJ 3Qj.YwhVWeBdYhRNid4YERKoO1zYHIegtvLZbTNN5OjegB.UBFtU4J642ZAk VP7ZXOxpjKEqH0QjbQtvRNGTQPfbEzkaFDdHirs7Ad8wxC2NaTdRe1Goah7S kkN.MN7TQRbCvGCmvQxyfgPldY.Jf64tjSIqDA5LmahOltyFdSPDtbcIqE9q pS9jTj3Kmw.R4FValoBRsONIsvjqnS26Rw.8-
X-Yahoo-Newman-Property: ymail-3
X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9
Date: Wed, 23 Jun 2010 23:23:09 +0100
To: <storm@ietf.org>
From: "Mark S. Edwards" <marke@muttsnuts.com>
In-Reply-To: <C2D311A6F086424F99E385949ECFEBCB02ED59ED@CORPUSMX80B.corp. emc.com>
References: <C2D311A6F086424F99E385949ECFEBCB02162B4B@CORPUSMX80B.corp.emc.com> <690958.35528.qm@smtp111.biz.mail.re2.yahoo.com> <C2D311A6F086424F99E385949ECFEBCB02A28E1D@CORPUSMX80B.corp.emc.com> <473934.13068.qm@smtp114.biz.mail.mud.yahoo.com> <C2D311A6F086424F99E385949ECFEBCB02ED59ED@CORPUSMX80B.corp.emc.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; format=flowed
Subject: Re: [storm] iSCSI feature removal: SLP ?
X-BeenThere: storm@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: Storage Maintenance WG <storm.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/storm>, <mailto:storm-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/storm>
List-Post: <mailto:storm@ietf.org>
List-Help: <mailto:storm-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/storm>, <mailto:storm-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 23 Jun 2010 22:23:16 -0000

Looks ok to me.  I was trying to be diplomatic in case there were any 
SLP diehards out there waiting to be offended.

But since none have appeared over the parapet the hammer approach 
that effectively deprecates SLP as an interoperability mechanism suits me.

I agree that we should not specifically prohibit it's use, after all 
people are free to create and use any discovery mechanism they wish 
for their own purposes.  Could be SLP, could be LDAP or "Fred's 
Bird-Brained Resource Locator", none should be explicitly barred.

Mark.


At 21:25 23/06/2010, david.black@emc.com wrote:
>Mark,
>
> > So if pushed I'd write something like:
> >
> > "iSCSI equipment that need discovery functions beyond SendTargets
> > should implement iSNS for extended discovery management capabilities
> > and maximum interoperability."
> >
> > Since any unit that implements SLP or even LDAP as a discovery
> > mechanism is not going to interoperate with the majority of systems,
> > I'd hesitate to even mention them.  However, if anyone feels strongly
> > that SLP deserves some mention, then by all means do so, just please
> > don't assert it too strongly.
> >
> > One final point.  Given that iSNS has won the consensus argument, is
> > there a case for turning the "should' in the above sentence to
>"SHOULD" ?
>
>Yes, I would use "SHOULD" plus I would add text to say:
>
>         SLP has not been widely implemented or deployed for use with
>         iSCSI, therefore RFC 3121's recommendation that SLP be
>         implemented is no longer valid.
>
>This is one of those situations in which subtlety does not win style
>points (IMHO) but I don't think we need a recommendation that SLP
>"SHOULD NOT" be implemented.  In addition (as noted below), RFC 3721
>would need to be added to the list of RFCs that are updated by the
>combined iSCSI Internet-Draft.
>
>Any objections?
>
>Thanks,
>--David
>
>
> > -----Original Message-----
> > From: storm-bounces@ietf.org [mailto:storm-bounces@ietf.org] On Behalf
>Of Mark S. Edwards
> > Sent: Monday, June 07, 2010 7:00 AM
> > To: storm@ietf.org
> > Subject: Re: [storm] iSCSI feature removal: SLP ?
> >
> > Sorry for the delay.
> >
> > As you say, RFC3721 was more about guidance and was written before
> > there was any deployment experience.  At least the text says 'should'
> > rather than 'SHOULD'.  It might be nicer to all round if it could
> > just be removed and no extended discovery mechanism be mentioned, but
> > we have realities to consider such as an iSCSI array won't get
> > Microsoft certification unless it supports at least basic iSNS -
> > running code and consensus.
> >
> > The one good thing we have now is that iSNS is indeed now an IETF
> > protocol (RFC 4171) and the original argument for SLP was that it was
> > an existing RFC.  So the argument for using SLP ahead of iSNS is no
> > longer relevant.
> >
> > So if pushed I'd write something like:
> >
> > "iSCSI equipment that need discovery functions beyond SendTargets
> > should implement iSNS for extended discovery management capabilities
> > and maximum interoperability."
> >
> > Since any unit that implements SLP or even LDAP as a discovery
> > mechanism is not going to interoperate with the majority of systems,
> > I'd hesitate to even mention them.  However, if anyone feels strongly
> > that SLP deserves some mention, then by all means do so, just please
> > don't assert it too strongly.
> >
> > One final point.  Given that iSNS has won the consensus argument, is
> > there a case for turning the "should' in the above sentence to
>"SHOULD" ?
> >
> > Mark.
> >
> >
> > At 23:54 21/05/2010, Black_David@emc.com wrote:
> > > > Regarding the feature removal discussion, can I add SLP to the
>list ?
> > > >
> > > > The RFC 3721 states
> > > >
> > > > "iSCSI equipment that
> > > >        need discovery functions beyond SendTargets should at least
> > > >        implement SLP, and then consider iSNS when extended
>discovery
> > > >        management capabilities are required such as in larger
>storage
> > > >        networks.  It should be noted that since iSNS will support
>SLP,
> > > >        iSNS can be used to help manage the discovery information
>returned
> > > >        by SLP."
> > > >
> > > > The implication is that targets and initiators should expect to
>find
> > > > support for SLP before considering iSNS.
> > > >
> > > > I remember our first iSCSI appliance and we spent ages trying to
>get
> > > > SLP working because it the above wording effectively made it
> > > > mandatory.  SLP turned out to be a complete bust and was
>effectively
> > > > killed off when Microsoft refused to support it in their initiator
> > > > and in their target logo tests.
> > > >
> > > > The result is that today I doubt you could find a target or
>initiator
> > > > out there supporting SLP.
> > > >
> > > > For anybody that does still implement SLP we could change the
>wording
> > > > for SLP a little to remove the implied hierarchy, or just admit
>that
> > > > running code has created IETF consensus.
> > >
> > >This is interesting.  RFC 3720 (main iSCSI spec) never mentions
> > >SLP.  RFC 3721 is not a Standards Track RFC, but that's not a reason
> > >not to update it (if people will excuse the double negative).
> > >
> > >So, Mark, could you send an email to the list with proposed text on
> > >SLP that you'd like to see in the new consolidated iSCSI draft (no
> > >more than a few sentences, please)?  If that text (as revised) is
> > >acceptable to the WG, the result would go into the new consolidated
> > >iSCSI draft, and RFC 3721 would be added to the list of RFCs that
> > >are being updated by that draft.
> > >
> > >Thanks,
> > >--David
> > >----------------------------------------------------
> > >David L. Black, Distinguished Engineer
> > >EMC Corporation, 176 South St., Hopkinton, MA  01748
> > >+1 (508) 293-7953             FAX: +1 (508) 293-7786
> > >black_david@emc.com        Mobile: +1 (978) 394-7754
> > >----------------------------------------------------
> >
> > _______________________________________________
> > storm mailing list
> > storm@ietf.org
> > https://www.ietf.org/mailman/listinfo/storm