Dell PowerSwitch S4112F-ON OS10 Enterprise Edition User Guide Release 10.4.0ER - Page 649
iSCSI configuration notes, Con iSCSI optimization
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In an iSCSI session, a switch connects CNA servers (iSCSI initiators) to a storage array (iSCSI targets) in a storage area network (SAN) or TCP/IP network. iSCSI optimization running on the switch uses dot1p priority-queue assignments to ensure that iSCSI traffic receives priority treatment. iSCSI configuration notes • When you enable iSCSI optimization, the switch auto-detects and auto-configures for Dell EqualLogic storage arrays directly connected to an interface. iSCSI automatically configures switch parameters after connection to a storage device is verified. You must manually enable an interface to support a storage device that is directly connected to a port, but not automatically detected by iSCSI. • By default, iSCSI monitoring sessions listen on TCP ports 860 and 3260. Enable iSCSI session monitoring and the aging time for iSCSI sessions. • Configure the CoS/DSCP values applied to ingress iSCSI flows - create a class-iscsi class map in POLICY-CLASS-MAP mode. • iSCSI operation requires LLDP to be enabled. The DCBX application TLV carries information about the dot1p priorities to use when sending iSCSI traffic. This informational TLV is packaged in LLDP PDUs. You can reconfigure the 802.1p priority bits advertised in the TLVs. Configure iSCSI optimization The iSCSI protocol provides TCP/IP transport of storage traffic between servers and storage arrays in a network using iSCSI commands. 1 Configure an interface or interface range to detect a connected storage device. interface ethernet node/slot/port:[subport] interface range ethernet node/slot/port:[subport]-node/slot/port[:subport] 2 Enable the interface to support a storage device that is directly connected to the port and not automatically detected by iSCSI. Use this command for storage devices that do not support LLDP. The switch auto-detects and auto-configures Dell EqualLogic storage arrays directly connected to an interface when you enable iSCSI optimization. iscsi profile-storage storage-device-name 3 Configure DCBX to use LLDP to send iSCSI application TLVs with the dot1p priorities for iSCSI traffic in INTERFACE mode. lldp tlv-select dcbxp-appln iscsi 4 Return to CONFIGURATION mode. exit 5 (Optional) If necessary, re-configure the iSCSI TCP ports and IP addresses of target storage devices in CONFIGURATION mode. Separate TCP port numbers with a comma (0-65535; default 860 and 3260). iscsi target port tcp-port1 [tcp-port2, ..., tcp-port16] [ip-address ip-address] 6 Configure the QoS policy applied to the ingress iSCSI flows. Apply the service policy to ingress interfaces in CONFIGURATION mode. (Optional) Reset the default CoS dot1p priority (default 4) and/or the trusted DCSP value used for iSCSI traffic. Assign an internal qos-group queue (0 to 7) to dot1p (0 to 7) and DSCP (0 to 63) values in POLICY-CLASS-MAP mode. class-map type application class-iscsi policy-map type application policy-iscsi class class-iscsi set qos-group traffic-class-number set cos dot1p-priority set dscp dscp-value end service-policy type application policy-iscsi 7 Enable iSCSI monitoring sessions on TCP ports in CONFIGURATION mode. iscsi session-monitoring enable 8 (Optional) Set the aging time for the length of iSCSI monitoring sessions in CONFIGURATION mode (5 to 43,200 minutes; default 10). iscsi aging time [minutes] 9 (Optional) Reconfigure the dot1p priority bits advertised in iSCSI application TLVs in CONFIGURATION mode. The default bitmap is 0x10 (dot1p 4). The default dot1p 4 value is sent in iSCSI application TLVs only if you enabled the PFC pause for dot1p 4 traffic (pfc-cos dot1p-priority command). Converged data center services 649
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