Internet Small Computer Systems Interface (iSCSI) is an IP-based storage networking standard that is mainly used for linking hosts to storage devices. By transmitting SCSI commands over IP networks, iSCSI can facilitate block-level transfers over IP-based networks. The iSCSI architecture is similar to a client/server architecture. In this case, the client is an initiator, such as a Linux or Windows host that issues an I/O request, and the server is a target such as the PowerMax storage system.
iSCSI can leverage existing investments in Ethernet infrastructures and expertise. It can use an existing network infrastructure of Ethernet switches, IP routers, and network adapters instead of requiring additional hardware. With the introduction of higher speed Ethernet networking standards, iSCSI has steadily gained popularity as a deployed storage protocol in data centers because it can now deliver performance comparable to that of FC SAN. iSCSI provides additional types of host interfaces for the PowerMax storage system, giving customers a wide variety of choices for connectivity, combined with CHAP to address iSCSI security.