Dell EMC SmartFabric OS10 User Guide Release 10.5.0

iSCSI is a TCP/IP-based protocol that establishes and manages connections between servers and storage devices in a data center network. After you enable iSCSI, iSCSI optimization automatically detects Dell EMC EqualLogic storage arrays that are directly attached to switch ports. To support storage arrays where autodetection is not supported, manually configure iSCSI optimization using the iscsi profile-storage name command.

iSCSI optimization enables a switch to autodetect Dell EMC iSCSI storage arrays and autoconfigure switch ports to improve storage traffic throughput. The switch monitors iSCSI sessions and applies QoS policies on iSCSI traffic. iSCSI optimization operates with or without DCBX over an Ethernet network.

• iSCSI uses the current flow-control configuration by default. If you do not configure flow-control, iSCSI autoconfigures flow control settings so that receive-only is enabled and transmit-only is disabled.
• The switch monitors and tracks active iSCSI sessions, including port information and iSCSI session information.
• A user-configured iSCSI CoS profile applies to all iSCSI traffic. Use classifier rules to direct the iSCSI data traffic to queues with preferential QoS treatment over other data passing through the switch. Preferential treatment helps to avoid session interruptions during times of congestion that would otherwise cause dropped iSCSI packets.

In an iSCSI session, a switch connects CNA servers (iSCSI initiators) to a storage array (iSCSI targets) in a SAN or TCP/IP network. iSCSI optimization running on the switch uses dot1p priority-queue assignments to ensure that iSCSI traffic receives priority treatment.