22iSCSI OptimizationThis chapter describes how to configure internet small computer system interface (iSCSI) optimization,which enables quality-of-service (QoS) treatment for iSCSI traffic. The topics covered in this chapterinclude:• iSCSI Optimization Overview• Default iSCSI Optimization Values• iSCSI Optimization Prerequisites• Configuring iSCSI Optimization• Displaying iSCSI Optimization InformationiSCSI Optimization OverviewiSCSI is a TCP/IP-based protocol for establishing and managing connections between IP-based storagedevices and initiators in a storage area network (SAN).iSCSI optimization enables the network switch to auto-detect Dell’s iSCSI storage arrays and triggers aself-configuration of several key network configurations that enables optimization of the network forbetter storage traffic throughput. .iSCSI optimization also provides a means of monitoring iSCSI sessions and applying quality of service(QoS) policies on iSCSI traffic. When enabled, iSCSI optimization allows a switch to monitor (snoop) theestablishment and termination of iSCSI connections. The switch uses the snooped information to detectiSCSI sessions and connections established through the switch.iSCSI optimization allows you to reduce deployment time and management complexity in data centers.In a data center network, Dell EqualLogic and Compellent iSCSI storage arrays are connected to aconverged Ethernet network using the data center bridging exchange protocol (DCBx) through stackedand/or non-stacked Ethernet switches.iSCSI session monitoring over virtual link trunking (VLT) synchronizes the iSCSI session informationbetween the VLT peers, allowing session information to be available in both the VLT peers. You canenable or disable iSCSI when you configure VLT.iSCSI optimization functions as follows:• Auto-detection of EqualLogic storage arrays — the switch detects any active EqualLogic array directlyattached to its ports.• Manual configuration to detect Compellent storage arrays where auto-detection is not supported.• Automatic configuration of switch ports after detection of storage arrays.• If you configure flow-control, iSCSI uses the current configuration. If you do not configure flow-control, iSCSI auto-configures flow control settings so that receive-only is enabled and transmit-onlyis disabled. .460 iSCSI Optimization
