4 - Storage and I/O Networks

Abstract

This chapter deals with various storage and input/output (I/O) protocols and interfaces, commonly collectively called networks. Various storage and I/O protocols and interfaces exist to support different applications. Upper-Level Protocols, including Fibre Channel Storage Protocol (FCP), Fiber Connection (FICON), Internet Protocol (IP), Internet Storage Protocol such as the Internet Small Computer System Interface (iSCSI), and Remote Direct Memory (RDMA), are implemented on several interfaces including Fibre Channel, Ethernet, Universal Serial Bus, InfiniBand, and Parallel Storage Protocol such as the Small Computer System Interface (SCSI). A storage interface enables computers to communicate with storage devices (send and receive data). New technology such as iSCSI, Fibre Channel over IP (iFCP), and FICON over IP (FCIP) are being used to enable TCP/IP-based networks to further expand storage networking. Parallel SCSI and Ultra SCSI are still being used for direct attachment of some storage devices to servers and some clusters. Fibre Channel is replacing parallel SCSI in cluster applications, providing increased performance, capacity, distance, and ability to scale beyond parallel SCSI address limits.