Parallel sysplex planning

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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.

Note:
  1. IBM z17 (Model ME1) can only participate in an STP-only timing network.
  2. IBM z17 (Model ME1) can only communicate directly with IBM z17 (Model ME1), IBM z16® (Model A01), z15 T01, and z15 T02 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.
Important: The IBM z17 (Model ME1) system can be configured with 1, 2, 3 or 4 frames.
  1. 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.
    This graphic shows that the coupling facilities or server with internal coupling facilities should be in the center of an open area.
    • 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.
  2. Arrange the sysplex in two rows, with the fronts of servers and coupling facilities facing each other (see the illustration under Weight distribution and multiple systems). Allow a 1.22 meter (48 inch) 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.
    This graphic shows that the coupling facilities or server with internal coupling facilities should be in the center of an open area.
  3. Sysplex connections can be made using Coupling Express LR or ICA SR cabling.
  4. As the Parallel Sysplex grows, add new servers evenly on either side of the central coupling facilities.
    This graphic shows that the coupling facilities or server with internal coupling facilities should be in the center of an open area.
  5. 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.
    This graphic shows that the coupling facilities or server with internal coupling facilities should be in the center of an open area.

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 z17 (Model ME1), IBM z16 (Model A01), z15 T01,and z15 T02 machines and coupling facilities - may complicate your physical planning, but the basic strategies outlined here will result in a successful Parallel Sysplex environment.