Parallel sysplex planning
This chapter is intended to provide guidance to those customers who operate in a Parallel Sysplex® environment. A Parallel Sysplex typically involves multiple processors and coupling facilities, shared I/O devices, and a host of interconnection possibilities. Detailed planning for a Parallel Sysplex is essential to meet technical objectives, such as performance and high availability, within the constraints of a specific raised floor configuration. Different technologies for servers, links and coupling facilities affect your ability to configure a productive sysplex.
The basic premise for a successful Parallel Sysplex installation is to centralize the physical location of the coupling facilities, and then position the sysplex servers around that center. Servers can be placed side-to-side. In addition to bringing the servers closer to the coupling facility, placing your server side-to-side provides for better management of hot and cold air flow.
- IBM z16 Rack Mount can only participate in an STP timing network.
- IBM z16 Rack Mount can only communicate directly with IBM z16 Rack Mount Bundle, IBM z15® Model T02 , z15, z14 (Models ZR1, M01, M02, M03, M04, M05), z13®, and z13s using Coupling Express LR or ICA SR coupling links.
Following are some guidelines to help you better plan for multiple system interconnection. These are example configurations that would minimize the distance to the coupling facility.
- Position the coupling facilities (or servers with internal coupling facilities) in the center of
an open area of raised floor large enough to accommodate all of the servers and other coupling
facilities to which you want to connect.

- Use physical planning information for each type of server/coupling facility you intend to add to the Parallel Sysplex to help determine how much floor space you will need.
- Remember to consider weight distribution, service clearances, power, and cooling for each piece of equipment you want to include.
- Arrange the sysplex in two rows, with the fronts of servers and coupling facilities facing each
other. Allow a 1.22 m (48 in) aisle width between the rows. Although this may be a larger aisle than
you have used before, your Parallel Sysplex will
benefit from the improvement in cooling that a wider aisle provides. (See the illustration under
Cooling recommendations for the room.) Note: The system air flow illustration shows a minimum aisle width of 941 mm (37 in). Although this width is adequate for a congested computer room floor, it is the minimum you should use. An aisle 1.22 m (48 in) wide will better serve the cooling and cabling needs of a Parallel Sysplex configuration.

- Sysplex connections can be made using Coupling Express LR or ICA SR cabling. Note: If you are planning to use ICA SR cabling, you must place connected servers no further than 150 m (492 ft) from each other.
- As the Parallel Sysplex grows, add new
servers evenly on either side of the central coupling facilities.

- As the Parallel Sysplex evolves, it is
possible to add rows using Coupling Express LR or ICA SR coupling links to provide connectivity.
With the equipment in these new rows centered on the original central coupling facilities, the Parallel Sysplex now assumes the shape of a diamond.

By following these guidelines, you will be able to configure a Parallel Sysplex, using the minimum amount of floor space, that meets your performance and availability objectives. The use of technology combinations - IBM z16 Rack Mount Bundle, IBM z15 Model T02 , z15, z14 (Model ZR1, M01, M02, M03, M04, M05), z13, and z13s machines and coupling facilities - may complicate your physical planning, but the basic strategies outlined here will result in a successful Parallel Sysplex environment.