Options For Enhancing Tape I/O Performance; Fcip Fastwrite And Ostp - Brocade Communications Systems 8 Administrator's Manual

Fabric os fcip administrator’s guide
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Options for enhancing tape I/O performance

Options for enhancing tape I/O performance
There are two options available for enhancing open systems SCSI tape write I/O performance:
FCIP Fastwrite and OSTP are implemented together. FC Fastwrite is an FC-FC routing alternative
that disables the local Ethernet ports (ge0 and ge1), making it impossible to configure FCIP
Fastwrite and OSTP and FC Fastwrite on the same 7500 or FC4-18i blade. Refer to
"Fibre Channel Fast Write (FCFW)"
FC Fastwrite flows may be routed to another 7500 or FC4-18i blade on the FC network. This 7500
or FC4-18i blade may have active FCIP tunnels over an IP network. FC Fastwrite flows may be
passed through the FCIP tunnel, but only if the FCIP Fastwrite option is disabled on the tunnel.

FCIP Fastwrite and OSTP

When the FCIP link is the slowest part of the network, consider using FCIP Fastwrite and OSTP. FCIP
Fastwrite and OSTP are two features that provide accelerated speeds for read and write I/O over
FCIP tunnels in some configurations:
OSTP accelerates SCSI read and write I/Os to sequential devices (such as tape drives) over FCIP,
which reduces the number of round-trip times needed to complete the I/O over the IP network and
speeds up the process. To use OSTP, you must also enable FCIP Fastwrite.
Both sides of an FCIP tunnel must have matching configurations for these features to work. FCIP
Fastwrite and OSTP are enabled by turning them on during the tunnel configuration process. They
are enabled on a per-FCIP tunnel basis. See
Consider the constraints described in
features.
TABLE 12
FCIP Fastwrite
Each GbE port supports up to 2048 simultaneous
accelerated exchanges, which means a total of 2048
simultaneous exchanges combined for Fastwrite and
OSTP.
Does not affect FICON traffic
FCIP Fastwrite and FC Fastwrite are mutually exclusive.
Does not support multiple equal-cost path
configurations (see
configurations").
52
FCIP Fastwrite and Open Systems Tape Pipelining (OSTP)
FC Fastwrite
Using FCIP Fastwrite and OSTP
"FCIP Fastwrite and OSTP
for information about FC Fastwrite.
"Creating an FCIP tunnel"
Table 12
when configuring tunnels to use either of these
OSTP
Each GbE port supports up to 2048 simultaneous
accelerated exchanges, which means a total of 2048
simultaneous exchanges combined for Fastwrite and
OSTP.
Does not affect FICON traffic
OSTP uses FCIP Fastwrite, not FC Fastwrite.
Does not support multiple equal-cost path
configurations or multiple non-equal-cost path
configurations (see
configurations").
Appendix A,
on page 61 for details.
"FCIP Fastwrite and OSTP
Fabric OS FCIP Administrator's Guide
53-1001766-01

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