HP Mainframe Connectivity Design Guide

For director-specific information, see:
◦ “B-series FICON directors and fabric rules” (page 29)
◦ “C-series FICON directors and fabric rules” (page 46)
◦ “McDATA FICON directors and fabric rules” (page 63)
FICON and Fibre Channel intermix guidelines
Use care when designing and implementing an intermix SAN. Released microcode levels for Fibre
Channel SAN components may be different from the released levels for FICON SAN components.
In order to implement an intermix SAN, the microcode must be released and certified to support
both FICON and FCP in the same fabric or SAN, and must be certified for the servers and devices
connected to the fabric. This adds a greater level of complexity to your SAN implementation when
compared to a FICON-only or FC-only SAN, for both implementation and ongoing support.
Performance guidelines
The utilization goal for FICON ports is an average of 50% or less. This enables the application to
perform I/O transfers in the event of a port failure.
For cascaded FICON directors, configure a minimum of one ISL for every four FICON ports. Use
the same speed or higher-speed ports for ISLs at the ingress/egress FICON ports. Do not use a 1
Gb/s ISL to support 2 Gb/s or 4 Gb/s ingress/egress ports.
• 1 Gb/s—Configure a minimum of 0.5 buffer credit per km of ISL.
• 2 Gb/s—Configure a minimum of 1 buffer credit per km of ISL.
• 4 Gb/s—Configure a minimum of 2 buffer credits per km of ISL.
• 8 Gb/s—Configure a minimum of 4 buffer credits per km of ISL.
• 10 Gb/s—Configure a minimum of 6 buffer credits per km of ISL.
• 16 Gb/s—Configure a minimum of 8 buffer credits per km of ISL.
NOTE: Small transactions (such as Online Transaction Processing, used in the banking industry)
can require more buffer credits due to the inefficiency of moving small blocks of data across the
ISL.
For FICON P9500 and XP configurations, HP recommends using one SSID per LCU, with up to
256 volumes per SSID.
Cabling and record keeping
After completing the planning phase, you can configure your FICON SAN. During the configuration
phase, record details about the physical configuration.
To facilitate maintenance, observe the following:
• Record keeping
Record the cable connections on the configuration layout diagram. Record the WWN, port
number, and location of each CHPID and CU.
• WWN labels
On each port, affix a label that identifies the WWN, if necessary. HP storage systems are
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prelabeled with this information.
• Cable labels
Label both ends of each cable using numbers or color coding to help dress the cables.
156 FICON SAN best practices