RE: iSCSI Naming: WWUIs, URNs, and namespaces

["Thomas McSweeney" <rf42tpme@us.ibm.com>]

Marjorie,
                                                                      
 >The host name provides the level of uniqueness necessary            
 >to allow iSCSI to ensure further uniqueness within that host.       
                                                                      



Not all iSCSI devices have a host name;  some use DHCP for IP address
assignment, particularly initiators.  An initiator needs a name that is
more unique than just within its host, so the target can identify it
(imagine all the initiators named "WindowsLaptop").  It is even possible
for a target to use DHCP, if all the initiators find its IP address using
some means other than DNS (e.g., iSNS and/or SLP).  Also, this would enable
storage administrators to configure a "hot backup" of a target on a second
host, so they can temporarily move the data to a backup machine to perform
some maintenance on the primary machine, without reconfiguring the
potentially thousands of geographically widespread initiators.  You could
preconfigure the initiators with a primary hostname and a backup hostname
for the target, or use iSNS/SLP to learn its IP address.

Tom McSweeney
iSCSI Development, Storage Systems Group, IBM
Email: rf42tpme@us.ibm.com
Phone: (USA) 919-254-5634  (tie line: 444-5634)
Fax:   (USA) 919-254-0391  (tie line: 444-0391)