[dm-devel] [multipath] SCSI device capacity mess

[Lars Marowsky-Bree]

On 2004-10-27T11:51:42, Bryan Henderson <hbryan at us.ibm.com> wrote:

> >In addition verifying the size and stuff it could also check that the
> >paths really (still) point to the same device (by storing the LUN WWN in
> >the hw_handler context, for example)
> 
> Just to eliminate any ambiguity here, using terminology from the 
> standards:  A LUN is a logical unit number.  A WWN is a fibre channel port 
> or node name.  There's no such thing as a LUN WWN.  I presume you mean to 
> check the logical unit device identifier, which is the world wide unique 
> and persistent identifier of a logical unit.  (That's what you get (among 
> other things) from Page 0x83 of the SCSI VPD read from the LU).

Thanks for the clarification; EMC at least partially calls said
world-wide unique identifier the "LUN's WWN" though. And if we are
nitpicking, it's EVPD. ;-)



Sincerely,
    Lars Marowsky-Brée <lmb at suse.de>

-- 
High Availability & Clustering
SUSE Labs, Research and Development
SUSE LINUX AG - A Novell company