Attaching servers to IBM i using iSCSI

A basic iSCSI network consists of an IBM® i iSCSI target adapter and a System x or IBM BladeCenter blade iSCSI initiator adapter.

The target and initiator devices are connected over an Ethernet local area network (LAN). The iSCSI target for IBM i provides the storage devices for the iSCSI initiator. For an integrated Windows server, the iSCSI target also provides removable media devices and virtual Ethernet connections for the iSCSI initiator. Figure 1 illustrates a basic iSCSI network.

Figure 1. Basic iSCSI network

You need to configure both the iSCSI target and initiator adapters from IBM i. The iSCSI network is used for iSCSI traffic only.

There are two types of iSCSI target and initiator adapter implementations:

Software target or initiator (Ethernet NIC)

With a software target or initiator, the iSCSI protocol is implemented in the server operating system. Server resources (for example, CPU and memory) are used for the iSCSI protocol. The IBM i integrated server solution uses standard Ethernet network interface cards (Ethernet NICs) as software targets and initiators.

Hardware target or initiator (iSCSI HBA)

With a hardware target or initiator, the iSCSI protocol is implemented in firmware on the iSCSI adapter. The iSCSI protocol is offloaded from the server. The IBM i integrated server solution uses iSCSI host bus adapters (iSCSI HBAs) as hardware targets and initiators.

IBM i can use any combination of software-based or hardware-based iSCSI target adapters. The integrated server can use any combination of software-based or hardware-based iSCSI initiator adapters that are supported by the specific integrated server model and the operating system that is installed on the server. Either type of iSCSI initiator adapter can connect to either type of iSCSI target adapter.

Note: The level of support for software-based iSCSI initiator adapters (Ethernet NICs) depends on the integrated server operating system version.

See the IBM i iSCSI Solution Guide for information about supported iSCSI target and initiator adapters.