Dell POWEREDGE M1000E - Manual (Page 513)

iSCSI Optimization Commands 513
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iSCSI Optimization Commands
NOTE: The iSCSI commands are only supported on the PCM6348, PCM8024, and
PCM8024-k switches. The commands will have different capabilties depending on
the switch. CLI commands and Dell OpenManage Switch Administrator pages are
not available for other switch models.
iSCSI Optimization provides a means of performing configuration specific to
storage traffic and optionally giving traffic between iSCSI initiator and target
systems special Quality of Service (QoS) treatment.
iSCSI Optimization is best applied to mixed-traffic networks where iSCSI
packets constitutes a portion of overall traffic. In these cases, the assignment
of iSCSI packets to non-default CoS queues can provide flows with lower
latency and avoid queue resource contention.
If iSCSI frames comprise most of the traffic passing through the switch, the
system provides optimal throughput when all traffic is assigned to the default
queue. An example of this situation is a Storage Area Network (SAN) where
the switch is dedicated to interconnecting iSCSI Targets with Initiators.
Using the default queue for this homogenous traffic provides the best
performance in traffic burst handling and the most accurate 802.3x Flow
Control Pause Frame generation. In these cases, the application of QoS
treatment other than the default policy may result in less overall throughput
or more packet loss.
Configuration consists of globally setting the MTU size to jumbo frames and
enabling flow control. By default, iSCSI optimization is disabled and iSCSI
QoS treatment is disabled.
LLDP is used to detect the presence of EqualLogic storage arrays. When
iSCSI optimization is enabled, and LLDP detects an EQL array on a port,
that port configuration is changed to enable portfast and disable unicast
storm control. Configuration changes appear in the running config and are
not removed by disabling the feature or disconnecting the EQl array.
2CSPC4.XModular-SWUM200.book Page 513 Thursday, March 10, 2011 11:18 AM