Cisco Systems SN 5428-2 manual Database, Webserver2000, 1 Target-and-LUN Mapping Example

Chapter 1 Before Configuring SN 5428-2 Storage Router Software

SCSI Routing Overview

If the LUN is available, it is made available as an iSCSI LUN and numbered with the iSCSI LUN number specified. For example, if an iSCSI target and iSCSI LUN specified as Database, LUN 9 were mapped to the physical storage address, WWPN 3100112233445566, LUN 12, then LUN 12 would be available as one iSCSI LUN. An iSCSI driver would see the iSCSI target named Database, with one iSCSI LUN identified as LUN 9. The iSCSI LUN would appear as one storage device to a host. (See Table 1-1.)

Table 1-1 Target-and-LUN Mapping Example

Apparent to Host as	iSCSI Target	iSCSI LUN	Physical Storage	Physical LUN
Local Disk	Name	Available	Address	Available
Local Disk (D:)	Database	LUN 9	WWPN	LUN 12
			3100112233445566
Apparent as one	Database	iSCSI LUN is	Specifies the storage	The LUN number
locally attached	appears as one	numbered as	address of a storage	is specified as the
storage device.	controller with	specified and	controller.	only LUN to be
	one LUN	can be different		mapped.
	available.	than the
		physical LUN
		number.

With target-only mapping, an iSCSI target name is specified and mapped to the physical storage address of a storage controller only; a WWPN. Any LUNs that are available in the storage controller are made available as iSCSI LUNs and are numbered the same as the LUNs in the storage controller. For example, if an iSCSI target specified as Webserver2000 were mapped to the physical storage address WWPN 3100112233445577, and LUNs 0 through 2 were available in that controller, those LUNs would become available as three iSCSI LUNs. An iSCSI driver would see the iSCSI target named Webserver2000 as a controller with three iSCSI LUNs identified as LUN 0, LUN 1, and LUN 2. Each iSCSI LUN would appear as a separate storage device to a host. (See Table 1-2.)

Table 1-2 Target-only Mapping Example

Apparent to Host as	iSCSI Target	iSCSI LUNs	Physical Storage	Physical LUNs
Local Disk	Name	Available	Address	Available
Local Disk (D:)	Webserver2000	LUN 0	WWPN	LUN 0
			3100112233445577
Local Disk (E:)	Webserver2000	LUN 1	WWPN	LUN 1
			3100112233445577
Local Disk (F:)	Webserver2000	LUN 2	WWPN	LUN 2
			3100112233445577
Apparent as three	Webserver2000	iSCSI LUNs	Specifies the storage	LUNs 0, 1, and 2
locally attached	appears as one	are numbered	address of a storage	are available for
storage devices.	controller with	the same as	controller.	mapping.
	LUNs 0, 1, and	physical LUNs.
	2 available.

Cisco SN 5428-2 Storage Router Software Configuration Guide

OL-4691-01 1-7