Advantech ASR-5300I Series, Руководство пользователя

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47 ASR-5300I Series Hardware User Manual
Chapter 3
S
ystem
Connection
3.5 iSCSI-Host RAID Connections
Ethernet Cable Requirements
 Ethernet cables must be supplied by the user. We recommend Cat5e-shielded
STP-type network cables or superior performance cables (to satisfy the require-
ments specified by emission standards).
 Straight-through Ethernet cables with RJ-45 plugs.
 Cross-over cables can be automatically detected and re-routed for a valid con-
nection.
Connection Types
 Direct to iSCSI initiators (software or hardware) or via Gigabit Ethernet
switches.
 To servers equipped with iSCSI HBA – preferably a hardware TOE (TCP/IP
Offload Engine) card, and then to client stations with an Ethernet NIC or iSCSI
HBA.
 The system presents its logical volumes through SCSI-like IDs and LUNs.
These RAID volumes then appear as iSCSI targets through the network.
3.5.1 Network and Host Connection Topologies
The iSCSI host ports connect to Ethernet network devices and iSCSI initiators that
comply with the IETF iSCSI standard (RFC 3720). The network connections of the
iSCSI ports are flexible. The use of network connecting devices, subnet, Name Serv-
ers, or iSCSI management software varies for each case. In the following sections,
configuration diagrams are provided to illustrate the potential uses of the EonStorDS
system in an iSCSI network.
Host NIC ports and the storage system’s iSCSI host ports must be configured into the
same subnet.
Please note the following information:
 Use the Ethernet management port for management purposes only, for exam-
ple, for SANWatch or a telnet console. This Ethernet management port should
not be used for I/O transactions.
 Configurations such as a subnet or Virtual LAN can separate iSCSI host links,
reduce overheads, and eliminate the impact of link failure.
 Multiple arrays or logical partitions can be created and made available
separately through different IDs or LUN numbers on the host ports. A RAID5
logical drive of eight members typically offers optimal array performance.
Note! Although iSCSI initiator software provides a cost-effective means for
building an iSCSI SAN, initiator software increases the workload of the
server CPU. We recommend employing the iSCSI HBAs provided with
TCP/IP offload engines to reduce overheads.