SANRAD I3.1.1205 - Manual (Page 120)

7-2 SANRAD V-Switch CLI User Manual
Introduction to Volume Exposure &
Security
iSCSI Targets
Data is able to be transferred via iSCSI when an iSCSI initiator establishes a TCP
connection with an iSCSI target.
ƒ The iSCSI initiator resides in the host computer and is configured by
the system administrator.
ƒ The iSCSI target resides in the V-Switch and is created by the volume
manager.
To enable iSCSI communications over TCP, the system administrator
configured portals during the initial V-Switch configuration, consisting of a
network port IP address and its assigned TCP port. Please see Chapter 4
“
Configuring iSCSI Portals ”for more details. Each configured portal is
automatically attached to all iSCSI targets created. Typically, there are few
portals and many targets.
Both iSCSI initiators and targets have a World Wide Unique Identifier (WWUI) of
up to 256 free form characters, e.g. www.sanrad.vswitch1.target1.
You create a V-Switch target by assigning an alias and WWUI to it.
You assign a Logical Unit Number (LUN) to a volume and then attach the LUN
to an iSCSI target to expose the volume to hosts.
When creating targets, keep in mind that:
ƒ Each target can have multiple LUNs.
ƒ Each target must have LU0 to be functional.
ƒ Each target should be exposed by only one V-Switch in a cluster.
ƒ Each target can be accessed by multiple hosts.
There are two ways to create a LUN and target:
ƒ Assign a LUN and create a target together.
ƒ Create targets first and later assign LUNs to the pre-created targets.
The V-Switch in Figure 7-1, contains three iSCSI targets: Target 1, Target 2 and
Target 3. It has two portals: (IP1, 5003) and (IP2, 5003). Target 1 and Target 2
have only one volume attached to each. Therefore, each volume is
automatically assigned LU0. Target 3 has two attached volumes, LU0 and LU1.