HP Mainframe Connectivity Design Guide

Connect ports on a channel card to different fabrics.
• Connect channel ports and storage ports to multiple interface cards on the director.
This ensures that an interface card failure on the director has minimum impact on data
availability.
• Use multiple paths.
This ensures that each LPAR on the mainframe and each LCU in the storage system has at least
two paths to the FICON SAN fabric.
• Use multiple ISLs between directors.
Configure at least two ISLs between a pair of directors. Add ISLs as data throughput requirement
increases. For more information, see “Recommended ISL ratios” (page 18).
• Connect ISL ports to multiple interface cards on the director.
In the event of an interface card failure in the director an alternate data path is available.
• Avoid using FICON and FCP on the same ISL.
This ensures that FCP data traffic does not interfere with the FICON traffic.
• Avoid using DASD and tape devices on the same ISL.
This ensures that the tape I/O transfers (typically large blocks of data) do not interfere with
DASD I/O activity (typically small blocks of data).
• Configure ISL trunking, port channels, or open trunking.
Use the model-specific method to evenly distribute the data traffic over multiple ISLs and ensure
automatic distribution of the workload in the event of an ISL failure.
• FICON Accelerators require single FCIP paths.
When using a FICON Accelerator, follow the special rules regarding FCIP ISLs. For B-series,
a single FCIP Tunnel or TI Zones must be configured. For C-series, VSANs must be configured
with only one FCIP ISL. This ensures all commands, data, and status information for each
emulated device uses the same FCIP path all the time, as required for the accelerators.
• Configure the switch ID to match the domain ID, and ensure that the ID is unique for each
director.
The mainframe HCD requires that all directors within an HCD configuration be assigned a
unique ID, even if they are in separate fabrics.
Unique IDs ensure accurate device identification in the event of a failure, and allow for future
fabric merging.
NOTE: The vendor domain ID defaults are as follows: Brocade = x'01', Cisco = x'01',
McDATA = x'60'.
• Configure and enable CUP on the FICON directors.
Configure a minimum of two paths to each CUP address (x'FE') on each FICON director.
◦ Required if the mainframe monitors or manages the FICON director
◦ Highly recommended to allow SMF data to be gathered from the director for RMF reports
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See “SAN scaling” (page 11) ( FICON CUP bullet)
• Ensure that all directors in the FICON SAN are from the same model family or vendor.
• If you implement an intermix environment, separate FICON and FCP ports into different zones,
VSANs, Open VSANs, or SAN LPARs.
FICON SAN design 155