Cisco Systems SN 5428-2 manual Transparent SCSI Routing Mapping and Access Control, 1-12

Chapter 1 Before Configuring SN 5428-2 Storage Router Software

Transparent SCSI Routing Overview

Basic Network Structure

Figure 1-12shows the basic structure of a transparent SCSI routing network. IP hosts with iSCSI drivers access the storage routers through an IP network connected to one of the Gigabit Ethernet interfaces of each storage router. The storage routers access the intelligent storage array through a Fibre Channel interface of each storage router. A management station manages the storage routers through an IP network connected to the management interface of each storage router. High availability operation for transparent SCSI routing is controlled in the intelligent storage array; therefore, an SN 5428-2 HA network is not necessary, and the HA interface on the SN 5428-2 is disabled.

Figure 1-12 Transparent SCSI Routing Basic Network Structure

Cisco SN 5428-2

IP host	Contains iSCSI
	driver

FC

Intelligent storage

Managementarray station

IP	Management
Contains iSCSI	FC
driver
IP host
Cisco SN 5428-2

85730

Transparent SCSI Routing Mapping and Access Control

Transparent SCSI routing occurs in an SN 5428-2 Storage Router through two types of mapping:

•Mapping iSCSI targets to physical targets

•Mapping each IP host to a Fibre Channel (FC) address

Mapping iSCSI targets to physical targets makes the physical targets accessible to IP hosts. Mapping each IP host to an FC address—which maps the iSCSI client in the IP host to the internal FC initiator WWPN—allows the host to be presented to a storage array as an FC host with its own FC WWPN.

Mapping iSCSI targets to physical targets consists of creating iSCSI targets that represent physical targets in an intelligent storage array. An iSCSI target is an arbitrary name for a group of physical storage devices; one iSCSI target is automatically created for each target made available by the intelligent storage array.

The iSCSI target name is created automatically using the iSCSI extended unique identifier (EUI) format. The EUI format combines the prefix “eui” with each WWPN made available by the intelligent storage array. For example, if the WWPN of a target in a storage array were 3100112233445566, then an iSCSI target would be created in the SN 5428-2 with the iSCSI target name of eui.3100112233445566.

Transparent SCSI routing maps iSCSI targets to physical targets using target-only mapping. Target-only mapping maps an iSCSI target to a physical storage target and its LUNs. Any LUNs that are available with a physical WWPN in the storage array are available with the corresponding iSCSI target and are numbered the same as the LUNs in the storage array.

Cisco SN 5428-2 Storage Router Software Configuration Guide

1-12 OL-4691-01