Cisco DS-C9216I-K9, Руководство по настройке

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24-21
Cisco MDS 9000 Fabric Manager Switch Configuration Guide
OL-7753-01
Chapter 24 Configuring IP Storage
Configuring FCIP
Figure 24-13 FCIP Link Write Acceleration
In Figure 24-13 , some data sent by the host is queued on the target before the target issues a Transfer
Ready. This way the actual write operation may be done in a less time than the write operation without
the write acceleration feature being enabled.
Tip
FCIP write acceleration will not work if the FCIP port is part of a PortChannel or if there are multiple
paths with equal weight between the initiator and the target port. Such a configuration might cause either
SCSI discovery failure or broken write or read operations.
Enabling FCIP Compression
The FCIP compression feature introduced in Release 1.3(x) allows IP packets to be compressed on the
FCIP link if this feature is enabled on that link. By default the FCIP compression is disabled.
This feature uses the Lempel-Zif-Stac (LZS) compression algorithm to compress packets.
The high-throughput mode allows faster compression but the compression ratio may be lower. The
high-comp-ratio mode allows a higher compression ratio, but the throughput may be lower.
FC FC
FCIP over
WAN
105224
Initiator MDS 9000 MDS 9000 Target
Transfer ready
Transfer ready
Transfer ready
Command
Command
Data transfer
Data transfer
Status
Status
Without
acceleration
RTT1
RTT1
RT2
FC FC
FCIP over
WAN
Initiator MDS 9000 MDS 9000 Target
With
acceleration