iSCSI technologies in HP ProLiant servers using advanced network adapters, 2nd edition

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Abstract
This technology brief explains iSCSI technologies you will find in HP ProLiant servers. It also explains
how these simple and cost-effective technologies benefit your data center. It covers the accelerated
iSCSI implementation for embedded and optional multifunction NICs. It also describes the full offload
iSCSI functionality available on HP FlexFabric adapters. These adapters are integrated onto some G7
HP BladeSystem servers and are available as mezzanine cards for G6 BladeSystem servers.
Introduction
iSCSI is a standard that implements the SCSI protocol for interacting with storage devices over a
TCP/IP network, typically over Gigabit Ethernet. Like Fibre Channel (FC), iSCSI lets servers access
shared storage devices over a network. Unlike FC-SAN, iSCSI does not require a separate, special
purpose network. This reduces the cost and complexity of having shared network storage.
As part of the iSCSI working group of the Internet Engineering Task Force (IETF), HP engineers had
hands-on involvement in writing the iSCSI specification. HP also developed the first multifunction
network adapter that combined Ethernet and iSCSI capabilities in a single network card, including
support for TCP/IP offload engine (TOE) and iSCSI acceleration.
iSCSI message exchange
iSCSI follows the SCSI architectural model which is based on message exchange between an initiator
and a storage resource, or target (Figure 1).