Dell PowerConnect 54 Series, User Manual

Page: 207 / 416

Configuring System Information
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Optimizing iSCSI
iSCSI is a communication protocol used for sending data between file servers and storage disks. The file
servers are called
initiators and the disks are called targets . You can optimize iSCSI flow by setting Quality
of Service frame priority parameters in the device. The device can also intercept iSCSI frames and provide
information about iSCSI communications (called sessions).
Configuring iSCSI Global Parameters
The iSCSI Optimization Global Parameters page includes parameters that affect how the device handles
iSCSI frames.
iSCSI can be configured for QoS. In the
iSCSI Optimization Global Parameters page, you must enable
iSCSI, set its classification to CoS or DSCP, and enable Remark (user priority). In the QoS pages, you can
then set the queueing to
strict priority or WRR , and then map the CoS or DSCP to the desired queue. You set
the queueing in the Qos Queue Settings page, and you map to queues in the QoS CoS to Queue or DSCP
to Queue pages.
Be careful when setting QoS parameters. For example, if you set the queueing to WRR and set a low weight,
iSCSI traffic will be dropped whenever there is an overload.
To open the
iSCSI Optimization Global Parameters page, click System → iSCSI Optimization → Global
Parameters in the tree view.
Figure 6-94. Global Parameters
• iSCSI Status — Whether iSCSI Optimization is enabled on the device. The default value is enabled .
• Classification — Whether priority of iSCSI packets is determined by CoS or DSCP. Select the
classification and then choose the desired value.
• Remark — Whether iSCSI remarks are enabled on the device.
• iSCSI Aging Time — How long the device will wait after the last received frame of an iSCSI session
before deleting the session from the list.