HP-UX iSCSI Software Initiator Support Guide, HP-UX 11i v1 and 11i v2, July 2005

Chapter 5
Management
ioscan
54
ioscan
After the iSCSI Software Initiator is installed, a virtual node will appear in the ioscan output. This virtual
node will appear as follows:
iscsi 0 255/0
When data is available for valid iSCSI targets, the output of the ioscan command for iSCSI targets will be
similar to the following example:
iscsi 0 255/0 iscsi CLAIMED VIRTBUS iSCSI VirtualNode
ext_bus 2 255/0/0.0 iscsial CLAIMED INTERFACE iSCSI-SCSIProtocolInterface
target 5 255/0/0.0.0 tgt CLAIMED DEVICE
disk 2 255/0/0.0.0.0 sdisk CLAIMED DEVICE <<a disk description>>
disk 3 255/0/0.0.0.1 sdisk CLAIMED DEVICE <<a disk description>>
The first line of the sample ioscan output displays the iSCSI virtual node. This is the root node for all iSCSI
storage and will occur only once in the ioscan output. The iSCSI transport driver claims the iSCSI root node.
The second line of the sample ioscan output displays the initiator session identifier instance (ISID) and the
SCSI-2 virtual bus. This implies that the ioscan operation was able to successfully establish a discovery
session (session instance is 0) with the iSCSI target identified in the registry. It also implies that storage was
defined behind the iSCSI target. The storage behind the target was defined in the SCSI-3 range of LUNs
0-127; therefore, virtual bus 0 was created. The driver iscsial (iSCSI adaptation layer) claimed the bus as an
iSCSI virtual bus, and the iscsial driver component will control operations to this bus.
The third line of the sample ioscan output displays a SCSI-2 target. SCSI-2 permits 16 targets per bus,
therefore, every eighth LUN on the iSCSI target (using SCSI-3) maps to a new SCSI-2 target.
The fourth and fifth lines of the sample ioscan output display SCSI-2 LUNs. SCSI-2 defines 8 LUNs per
target, therefore, every eighth LUN on the iSCSI target will map to LUN 0 for a new SCSI-2 target. The
SCSI class drivers, in this case the sdisk class drivers, claim the disk LUNs.