Fcip Write Acceleration - Cisco MDS 9000 series Configuration Manual

Chapter 2 Configuring FCIP
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
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FCIP Write Acceleration

The FCIP write acceleration feature enables you to significantly improve application write performance
when storage traffic is routed over wide area networks using FCIP. When FCIP write acceleration is
enabled, WAN throughput is maximized by minimizing the impact of WAN latency for write operations.
The write acceleration feature is disabled by default and must be enabled on both sides of the FCIP link.
Note
If it is only enabled on one side of the FCIP tunnel the write acceleration feature will be turned
operationally off.
In Figure
while the WRITE command with write acceleration only requires one RTT. The maximum sized Transfer
Ready is sent from the host side of the FCIP link back to the host before the WRITE command reaches
the target. This enables the host to start sending the write data without waiting for the long latency over
the FCIP link of the WRITE command and Transfer Ready. It also eliminates the delay caused by
multiple Transfer Readys needed for the exchange going over the FCIP link.
OL-19525-01,Cisco MDS NX-OS Release 4.2(1)
FCIP Write Acceleration, page 2-25
Configuring FCIP Write Acceleration, page 2-27
Displaying Write Acceleration Activity Information, page 2-27
FCIP Tape Acceleration, page 2-28
Configuring FCIP Tape Acceleration, page 2-32
Displaying Tape Acceleration Activity Information, page 2-33
FCIP Compression, page 2-34
Configuring FCIP Compression, page 2-36
Displaying FCIP Compression Information, page 2-36
2-13, the WRITE command without write acceleration requires two round-trip transfers (RTT),
Cisco MDS 9000 Family NX-OS IP Services Configuration Guide
Configuring FCIP
2-25