Cisco DS-X9530-SF1-K9 - Supervisor-1 Module - Control Processor Configuration Manual page 748

Advanced FCIP Features
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 .
Figure 33-9 FCIP Link Tape Acceleration
Backup
Server
FCIP tape acceleration does not work if the FCIP port is part of a PortChannel or if there are multiple
Tip
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.
When tape acceleration is enabled in an FCIP interface, a FICON VSAN cannot be enabled in that
Caution
interface. Likewise, if an FCIP interface is up in a FICON VSAN, write acceleration cannot be enabled
on that interface.
When you enable the tape acceleration feature for an FCIP tunnel, the tunnel is reinitialized and the write
acceleration feature is also automatically enabled.
In Tape Acceleration after a certain amount of data has been buffered at the remote Cisco MDS switch,
the write operations from the host are flow controlled by the local Cisco MDS switch, by not proxying
the Transfer Ready. On completion of a write operation when some data buffers are freed, the local Cisco
MDS switch resumes the proxying.
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 12MB).
We recommend that you use the default option for flow control buffering.
Tip
Do not enable time stamp control on an FCIP interface tape acceleration configured.
Tip
Cisco MDS 9000 Family Configuration Guide
33-22
MDS with
IPS
Write Command 1
Status 1
Write Command N
Write Command N
Status N
WRITE FILEMARKS operation
WRITE FILEMARKS status
MDS with
IPS
WAN
Write Command 1
Write Command 1
Write Command N
WRITE FILEMARKS operation
Chapter 33
Tape
Drive
FC FC
Status 1
Status N
OL-6973-03, Cisco MDS SAN-OS Release 2.x
Configuring FCIP