HP Mainframe Connectivity Design Guide

◦ Allow additional bandwidth for growth.

◦ If you need to resynchronize volumes due to a disaster, consider how long

resynchronization will take over the allocated bandwidth. To reduce the resynchronization

time, allocate additional bandwidth.

• Divide your data into tiers, with the most critical data in the highest tier. Depending on the

asynchronous replication application, you can specify an update time cycle for each tier or

consistency group so that the most critical data is updated more frequently than less critical

data.

• Most IP networks do not manage bandwidth for each network connection. As network traffic

increases, bandwidth allocated to the replication application may be used by the network.

To minimize impact on performance:

◦ Use dedicated circuits to create separate networks for your enterprise data.

◦ Guarantee the bandwidth and QoS using a third-party router and/or a QoS vendor.

◦ Create VPNs through your local routers.

◦ Use the shortest possible distance between remote sites because distance affects the

amount of data you can transmit over a link.

Consider the following best practices:

• Do not mix FICON and FCP on the same ISL or FCIP link.

This is prohibited by some FCIP gateways.

• Ensure that DASD and tape are on separate ISLs or FCIP links. If DASD and tape must be on

the same ISL, schedule the peak periods to occur at different times of the day. For example,

do tape batch processing in the middle of the night when DASD replication uses less bandwidth.

• Use an FCIP gateway that provides emulation functions to improve throughput over long

distances:

◦ Disk acceleration or disk streaming for controller-to-controller disk replication methods

such as HP P9000/XP Continuous Access software

◦ FICON tape acceleration or tape emulation for tape, VTS, or VSM implementations

◦ FICON XRC emulation for XRC implementations

Emulation and acceleration methods vary by FCIP gateway product. For more information, contact

an HP storage representative.

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