HP-UX iSCSI Software Initiator Support Guide (Edition 7)

Figure 9 HP-UX iSCSI Software Initiator Block Diagram
2.3 Targets
The iSCSI Software Initiator is interoperable with all iSCSI Protocol Specification (RFC 3720)
compliant targets. No component of the iSCSI Software Initiator implementation is, in any way,
HP proprietary.
The iSCSI Software Initiator supports the static discovery of targets and, optionally, the dynamic
discovery of targets.
2.3.1 Hardware Path Representation
The iSCSI virtual Host Bus Adapter (HBA) is defined in the IO tree with respect to a virtual root
node, which will always have a value of 64,000. The hardware path for iSCSI targets is built off
of this virtual HBA node, instead of being built off of a physical HBA node, as is currently done
with Fibre Channel and parallel SCSI targets. The interaction between the iSCSI session and a
physical HBA is abstracted in the virtual HBA.
The external representation of the hardware path for an iSCSI lunpath is:
• 64000/<iscsi>/<iscsi_virtual_HBA>.<session_instance>.<lunpath>
where:
• <iscsi> in the hardware path represents the root I/O node of the iscsi driver. The value of this
element is assigned dynamically by the HP-UX I/O infrastructure.
• <iscsi_virtual_HBA> represents the iSCSI S/W initiator..
• <session_instance> is the iSCSI session instance number. The iSCSI session defines a SCSI
I-T nexus for transactions between the iSCSI initiator and the iSCSI target.
• <lunpath> is the representation of a SCSI-3 logical unit number.
The iSCSI lun hardware path representation is same as that of any other lun in 11i v3. For more
information, see the 11i v3 SCSI services white papers at:
http://docs.hp.com/en/oshpux11iv3.html#Storage%20Area%20Management
The hardware path for iSCSI targets will be persistent across reboots. It is maintained in the
/etc/ioconfig file and used during system startup to reconstruct the IO tree.
2.3 Targets 13