Logical unit numbers (LUNs) created on an iSCSI disk storage subsystem are not directly assigned to a server. For iSCSI, LUNs are assigned to logical entities called targets.
Targets are created in order to manage the connections between an iSCSI device and the servers that need to access it. A target defines the portals (IP addresses) that can be used to connect to the iSCSI device, as well as the security settings (if any) that the iSCSI device requires in order to authenticate the servers that are requesting access to its resources.
Servers that require access to a LUN have to connect to the target to which the LUN is assigned. To connect to a target, a server in the storage area network (SAN) uses an iSCSI initiator. An iSCSI initiator is a logical entity that enables the server to communicate with the target. The iSCSI initiator first logs on to the target. The target must grant access before the server can start reading and writing to all LUNs that are assigned to that target.
With Storage Manager for SANs, you can create targets for the iSCSI subsystems in your SAN, configure the security settings for these targets, and start logon sessions with them.
This feature enables you to perform a select subset of the tasks that relate to iSCSI configuration and administration. You can also perform these and other tasks using the Microsoft iSCSI Initiator, which is included in Windows Server 2008 in Administrative Tools. Additionally, vendors of networking and storage solutions provide similar tools to perform iSCSI configuration and administration tasks. For more information about iSCSI, see http://go.microsoft.com/fwlink/?LinkId=102299.
In most cases, you can create and manage targets yourself. However, some iSCSI storage subsystems only support simple target configurations, where targets are automatically created when you create a LUN. With simple target configurations, you also cannot delete a target or manually assign LUNs to it. LUNs are automatically assigned when they are created. For this type of subsystem, you just need to identify the server or cluster that will access the LUN, and the iSCSI subsystem will enable access from that server or cluster to the LUN.