Cisco MDS 9000 series Configuration Manual page 55

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
amount of data has been buffered at the local Cisco MDS switch, the read operations to the tape drive
are flow controlled by the remote Cisco MDS switch by not issuing any further reads. On completion of
a read operation, when some data buffers are freed, the remote Cisco MDS switch resumes issuing reads.
The default flow control buffering uses the automatic option. This option takes the WAN latencies and
the speed of the tape into account to provide optimum performance. You can also specify a flow control
buffer size (the maximum buffer size is 12 MB).
We recommend that you use the default option for flow-control buffering.
Tip
Do not enable time-stamp control on an FCIP interface with tape acceleration configured.
Tip
If one end of the FCIP tunnel is running Cisco MDS SAN-OS Release 3.0(1) or later and NX-OS Release
Note
4.x, and the other end is running Cisco MDS SAN-OS Release 2.x, and tape acceleration is enabled, then
the FCIP tunnel will run only tape write acceleration, not tape-read acceleration.
In Cisco MDS NX-OS Release 4.2(1), the FCIP Tape Acceleration feature is not supported on FCIP
Note
back-to-back connectivity between MDS switches.
Tape Library LUN Mapping for FCIP Tape Acceleration
If a tape library provides logical unit (LU) mapping and FCIP tape acceleration is enabled, you must
assign a unique LU number (LUN) to each physical tape drive accessible through a target port.
Figure 2-16
provides LUN mapping, then all the four tape drives should be assign unique LUNs.
Figure 2-16
Host 1
Host 2
OL-19525-01,Cisco MDS NX-OS Release 4.2(1)
shows tape drives connected to Switch 2 through a single target port. If the tape library
FCIP LUN Mapping Example
FCIP link
Switch 1
Tape library
Drive 1
Switch 2
Drive 2
Drive 3
Drive 4
Cisco MDS 9000 Family NX-OS IP Services Configuration Guide
Configuring FCIP
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