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

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Figure 2. Message exchange between an initiator and target using the iSCSI protocol mode
Initiators include software initiators and hardware initiators (accelerated or offload HBAs). Software
initiators require CPU resources to manage the protocol stack. A more efficient approach is to offload
the protocol management to an iSCSI HBA, such as the HP NC551i Dual Port FlexFabric 10 Gb
Network Adapter
iSCSI functionality
iSCSI provides ProLiant servers ready access to storage resources using the same protocols that are
used for networking. Upgrading from direct attached storage (DAS) to iSCSI-connected storage gives
you greater flexibility and asset utilization. Using common infrastructure reduces complexity and cost.
Consolidating storage in a centralized pool using network attached storage leads to greater efficiency
because servers can have shared access to storage. You can also manage, resize, and protect the
network attached storage pool from a single control point.
Operating distance
It is possible for an iSCSI-based network to economically span great distances using commonly
available wide area networks (WANs). Longer operating distances lets you mirror and archive data
at remote sites to meet disaster protection and business continuity goals.
Security
IP networks have a well-defined security infrastructure (encryption and authentication) that makes
iSCSI viable for remote back up and disaster recovery applications. FC networks, on the other hand,
are primarily protected with physical security.
Encryption
An iSCSI transfer can optionally encrypt each packet, ensuring security until the packet is decrypted
by the receiver. A set of protocols developed by the IETF called Internet Protocol Security (IPSEC)