Chapter 4
Subsystem Connection and Operation
4.1 Connection
Overview
4.1.1 Cabling
Following are the requirements on the type of cables used to connect the
subsystem’s iSCSI host ports:
․
Ethernet cables are user-supplied. Cat5e shielded STP type network
cables or better performance types (important for meeting the
requirements imposed by emission standards). A shielded STP,
twisted-pair cable is available as an accessory.
․
Straight-through Ethernet cables with RJ-45 plugs.
․
Use of cross-over cables can also be automatically detected and re-
routed for a valid connection.
Connection:
․
Directly to iSCSI initiators (software or hardware) or via Gigabit
Ethernet switches.
․
To servers equipped with iSCSI HBA [better be a hardware TOE
(TCP/IP Offload Engine) card], and then to client stations with an
Ethernet NIC or iSCSI HBA.
․
The subsystem presents its logical volumes through SCSI-like IDs
and LUNs. These RAID volumes then appear as iSCSI targets
through the network.
NOTE:
Even though iSCSI initiator software is a cost-effective way of building
an iSCSI SAN, software initiator adds additional workload to the server
CPU. It is recommended to apply iSCSI HBAs that come with TCP/IP
offload engines in order to reduce overhead.
4-1
