S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
41-2
Cisco MDS 9000 Family CLI Configuration Guide
OL-16184-01, Cisco MDS SAN-OS Release 3.x
Chapter 41 Configuring the SAN Extension Tuner
About the SAN Extension Tuner
Figure 41-1
SCSI Command Generation to the Virtual Target
The SET feature assists with tuning by generating varying SCSI traffic workloads. It also measures
throughput and response time per I/ O over an FCIP link.
Before tuning the SAN fabric, be aware of the following guidelines:
•
Following these implementation details:
–
The tuned configuration is not persistent.
–
The virtual N ports created do not register FC4 features supported with the name server. This is
to avoid the hosts in the SAN from discovering these N ports as regular initiators or targets.
–
Login requests from other initiators in the SAN are rejected.
–
The virtual N ports do not implement the entire SCSI suite; it only implements the SCSI read
and write commands.
–
Tuner initiators can only communicate with tuner targets.
•
Verify that the Gigabit Ethernet interface is up at the physical layer (GBIC and Cable connected—an
IP address is not required).
•
Enable iSCSI on the switch (no other iSCSI configuration is required).
•
Create an iSCSI interface on the Gigabit Ethernet interface and enable the interface (no other iSCSI
interface configuration is required))(see the
“Creating iSCSI Interfaces” section on page 42-5
).
•
Configure the virtual N ports in a separate VSAN or zone as required by your network.
•
Be aware that a separate VSAN with only virtual N ports is not required, but is recommended as
some legacy HBAs may fail if logins to targets are rejected.
•
Do not use same Gigabit Ethernet interface to configure virtual N ports and FCIP links—use
different Gigabit Ethernet interfaces. While this is not a requirement, it is recommended as the
traffic generated by the virtual N ports may interfere with the performance of the FCIP link.
SAN Extension Tuner Setup
Figure 41-2
provides a sample physical setup in which the virtual N ports are created on ports that are
not a part of the FCIP link for which the throughput and latency is measured.
FC
FC
WAN/MAN
IPS
fabric
IPS
fabric
Virtual initiator
Virtual target
Read/Write I/O
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