Reference Guide

480 | iSCSI Optimization
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• iSCSI QoS — A user-configured iSCSI class of service (CoS) profile is applied to all iSCSI traffic.
Classifier rules are used to direct the iSCSI data traffic to queues that can be given 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 iSCSI packets to be dropped.
• iSCSI DCBx TLVs are supported.
Figure 25-1 shows iSCSI optimization between servers and a storage array in which a stack of three S5000
switches connect a server (iSCSI initiator) to storage arrays (iSCSI targets) in a SAN network. iSCSI
optimization running on the master switch is configured to use dot1p priority-queue assignments to ensure
that iSCSI traffic in these sessions receives priority treatment when forwarded on stacked switch hardware.
Figure 25-1. iSCSI Optimization Example