Talk:World Wide Name

Please take a look at the specs on this link... it has better explanation but needs to be verified and have permission from the original author (Chris Evans) before putting the same info in this page.

http://www.techworld.com/storage/features/index.cfm?featureid=156&pagtype=samecatsamechan

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This article doesn't say what a WWID or World Wide Name is used for within the network. Endpoints, resources, or what? —Preceding unsigned comment added by 124.186.110.146 (talk) 04:31, 11 February 2009 (UTC)

The answer to that is pretty much "yes". I tried to clear that up.(71.233.167.118 (talk) 03:48, 10 May 2012 (UTC))

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I fleshed this whole article out a tad (which included added a short description of the "mapped" format.) What I did not do was link to the separate WWNN/WWPN page, because those acronyms and terms are not distinct enough to merit a separate page. They should probably be just redirected to this article. To wit, those terms are now mentioned, and mentioned in the first paragraph. (71.233.167.118 (talk) 03:48, 10 May 2012 (UTC))

What does U/L mean?

This article uses "U/L" three times but does not explain what that means. 96.26.79.253 (talk) 13:56, 13 March 2014 (UTC)

See MAC_address#Address_details. They are the "unicast" and "local" bits in the MAC address. Don't know how to describe or link it appropriately… --RokerHRO (talk) 10:37, 6 July 2015 (UTC)

Do SAS drives actually use WWNs?

I see no indication from the SCSI Primary Commands, SCSI Block Commands, or Serial Attached SCSI references indicating that it is required. CTRL+F does not find a single reference to it. This page is misleading. FC does appear to have it supported, and ATA has it, but SCSI does not use this terminology at all. It has optional support for the WWN formats described in this page, but it is not required by the specification SAS:

SPC-5: 644 on describe the Device Identification page, but it does **not** mention this is a WWN.

Rattard (talk) 16:09, 18 September 2019 (UTC)

Some more investigation reveals that SAM describes using "World Wide" to describe a variety of identifying components (more aligned with what I would expect to be described here). They say that Logical Units, ports, and the individual components have world wide addresses.

3.1.58 logical unit name

name (see 3.1.64) of a logical unit that is world wide unique within the SCSI transport protocol of a SCSI domain in which the SCSI device containing the logical unit has SCSI ports (see 4.6.4.2)

3.1.64 name

label of an object that is unique within a defined context and should never change

The SAM model therefore classifies that a LU name only must be unique and fixed, not the contents of the format, specifically as defined on this page that it is "an 8 or 16 byte number.

SPC-4, which describes the field in which these are reported indicates: it can be:

1h (i.e., T10 vendor ID based);

2h (i.e., EUI-64-based);

3h (i.e., NA A); or

8h (i.e., SCSI name string).

with at least one being 2h, 3h, or 8h. This indicates that the format can be arbitrary UTF-8 text, in table 477 of that spec. NAA and EUI-64 are not required.

I think I would suggest that we specifically call out different sections for different protocols which share the same concepts. The header section describing WWWPN/WWNN for fibre channel could be a dedicated section. I think adding a section for SCSI might be relevant. Rattard (talk) 21:28, 24 September 2019 (UTC)

References