HP XP7 Continuous Access Synchronous for Mainframe Systems User Guide (TK911-96003)

• Set port topology to the following:
NL port: Fab on, FC-AL◦
◦ N port: Fab on, Point-to-Point
◦ Some switch vendors require F port (for example, McData ED5000).
• Host I/O response time can be improved on long distance switch connections by using host
mode options 49 and 50, or 51. The following table describes these options for the 16FC8
package. A HP-approved channel extender is required.
DescriptionHost mode optionsNo
Fixes higher values of buffer-to-buffer credits (BBCs) to increase data
transfer size over long distances
1
. This host mode option must be used
in conjunction with host mode option 50.
2
BB Credit Set UP
Option 1
49
Fixes higher values of buffer-to-buffer credits (BBCs) to increase data
transfer size over long distances
1
. This host mode option must be used
in conjunction with host mode option 49.
2
BB Credit Set UP
Option 2
50
Improves host I/O response time for long distance switch connections.
2
Round Trip Set UP
Option
51
1. Up to 100 km.
2. The microcode supporting these functions must be installed on both the primary and secondary system
Extender connection
The following figure shows an extender connection, in which channel extenders and switches are
used to connect the devices across large distances.
Figure 1 Extender Connection
• Set port topology to the following:
NL/FL port: Fab on, FC-AL◦
◦ F port: Fab on, Point-to-Point
• Best practice is to create at least two independent data paths (one per cluster) between the
primary and secondary system for hardware redundancy for this critical element.
48 Planning for Continuous Access Synchronous Z