RE: iSCSI Naming: WWUIs, URNs, and namespaces

["KRUEGER,MARJORIE (HP-Roseville,ex1)" <marjorie_krueger@hp.com>]

How does this relate to URLs?  Does this mean we can't specify a URL format
for iSCSI resources?  Can you provide the logic behind the IESG pronouncing
that the IESG won't approve another global namespace?  It sounds like the
logic the TCP group used to reject the need for framing first time round("If
we allowed every yahoo that wanted changes to the TCP header, TCP wouldn't
be what it is today..")

Its not clear to me why the N&D group thinks iSCSI devices need globally
unique names.  It seems like a host name is unique enough, and behind that
it's up to the host to ensure uniqueness locally.

Marjorie Krueger
Networked Storage Architecture
Networked Storage Solutions Org.
Hewlett-Packard
tel: +1 916 785 2656
fax: +1 916 785 0391
email: marjorie_krueger@hp.com 

> -----Original Message-----
> From: Black_David@emc.com [mailto:Black_David@emc.com]
> Sent: Thursday, March 22, 2001 9:48 PM
> To: ips@ece.cmu.edu
> Subject: iSCSI Naming: WWUIs, URNs, and namespaces
> 
> 
> <RANT> I don't like naming issues. </RANT> :-) :-)
> 
> After suitable consulting with some members of
> the IESG and IAB, I have some news to convey about
> the current approach to iSCSI naming.
> 
> The IESG will not approve another global namespace
> for iSCSI's use - this means that WWUIs as currently
> designed will need to be revised out of the
> naming and discovery draft, and that it will not be
> possible to proceed with the WWUI URN draft
> as an official IPS WG work item.  The best course of
> action would probably be to allow the WWUI URN draft
> to expire without further revision.
> 
> To a first approximation, WWUIs are/were a "grand
> unified theory" of naming, in that any namespace could
> be glued into the WWUI world (as several were).
> The WG is being directed to instead focus on the
> individual namespaces and make sure that the ones that
> are used are in fact necessary.  iSCSI can use text
> keys to identify which sort of name is being used
> (one key for each sort of format, for each instance
> in which a name is used), and it may be possible
> to encode the name format in the parse rules for the
> values of iSCSI keys to avoid proliferation of keys.
> 
> Taking a look at the namespaces in the current iSCSI
> naming and discovery draft, here's some initial
> guidance from this WG co-chair:
>   iscsi - canonical target -- This should be fine.
>   eui - WWNs -- The use of these for storage makes eminent
> 	sense.  I don't see a problem here.
>   dns - hostnames -- Use of these should be abandoned as
> 	not only are they not really URNs (as indicated
> 	in the draft), but their intended usage is straying
> 	into the tarpit known as "URN resolution".  Faster
> 	progress will made by staying out.  A DNS hostname
> 	can be put into an Alias or something new can be
> 	invented to carry it as a Location Hint, BUT the
> 	relevant URN WG RFCs and drafts on URN resolution
> 	should be reviewed before proceeding too far in this
> 	direction.
>   iscsi - Reverse DNS and oui - Org. Unique Identifier --
> 	The rationale for these is not clear to me.
> 	Assuming that WWNs are going to be available for
> 	use in naming iSCSI Initiators and Targets, what
> 	are the problems that these sorts of names solve
> 	that WWNs don't?  It appears that one of the problems
> 	may be who can get/create them.  Discussion of this
> 	on the list would be appropriate.
> In any case, the fewer name formats we have to deal with,
> the better.
> 
> I want to try to anticipate an objection to this, which
> would note that from a functional viewpoint the basic
> impact of this is to move some characters from one text 
> string to another (e.g., from a WWUI type designator
> to part of an iSCSI text key), and wonder if this is
> a distinction without a difference.  One of the reasons
> for the <RANT> that started this post is that a functional
> view is not sufficient for naming - how things are named,
> the intended usage of names and their scope matter a lot.
> This is particularly true when considering the structure
> of a namespace and how that structure may be extended.
> The upshot is that avoiding introduction of something
> claiming to be yet another global namespace is important
> (i.e., use existing namespaces with global scope in preference
> to inventing new ones).  The resulting need to define
> the name spaces/formats in the main iSCSI spec. is
> probably a "feature" as it forces us to pay more
> attention to the sorts of names we use and raises the
> bar for adding additional sorts of names in the future.
> 
> I will be working with
> the naming and discovery team in my "copious spare time"
> to make sure that we don't lose the valuable work and
> progress they've made to date as a consequence of this
> change.  Discussion on the list about what sort
> of names are important (e.g., the Reverse DNS and OUI
> namespaces) and why would be useful. 
> 
> Thanks,
> --David
> 
> 
> ---------------------------------------------------
> David L. Black, Senior Technologist
> EMC Corporation, 42 South St., Hopkinton, MA  01748
> +1 (508) 435-1000 x75140     FAX: +1 (508) 497-8500
> black_david@emc.com       Mobile: +1 (978) 394-7754
> ---------------------------------------------------
>