Adding a Coupling Facility

This topic has a procedure to add a coupling facility (CF) to an active sysplex.

Use HCD to create an IODF that defines the CF to the I/O configuration. See z/OS HCD Planning and z/OS HCD User's Guide for more information on defining coupling facility elements in a sysplex.
1. Create a new IODF containing the new CF control unit definition and channel path definitions that will be used to connect the CF to other images (z/OS® images as well as CF images).
2. Use the HCD Build IOCDS function to create and download an IOCDS containing the CF channel path definitions for remote IOCDS management.
Activate the new IODF on all images (both z/OS and CF).
The IODF can be dynamically activated on z/OS systems. To ensure that the required processing for changes to CF elements (CF control units or CF channel paths) will be executed, either specify SOFT=VALIDATE on the ACTIVATE system command, or choose the "Activate software configuration only and validate hardware changes" option from the HCD Activate New Configuration panel. SOFT=VALIDATE is a requirement in all N-1 partitions when changes to CF elements are made.
Verify the addition of the CF on all systems with the following system commands:
```
DISPLAY CF
DISPLAY M=CHP(chpxx,chpyy...) 
```
Ensure that any necessary hardware is installed (for example, ISC or ICB links) to provide connectivity between the z/OS image(s) and the CF. Connectivity must also be provided between coupling facilities that will be used for system-managed CF structure duplexing.
Ensure that CF CHPIDs are online. The following CF command can be used on a CF to configure a CF CHPID online:
```
CONFIGURE CHPID ONLINE
```
CHPIDs in use can be verified with the following CF commands:
```
DISPLAY CHPIDS
DISPLAY RESOURCES
```
See PR/SM™ Planning Guide for more information on coupling facility control code commands.
Create a new CFRM policy (or update an existing CFRM policy) that has a CF definition statement for the new CF to be added, and has the CF name added to all appropriate structure preference lists. See Planning a coupling facility policy for more information. Activate the new CFRM policy using the SETXCF START,POLICY,TYPE=CFRM,POLNAME=polname2 system command.
The CF should be added immediately to the CFRM active policy, but the addition of the CF to the preference list of allocated structures may remain pending until REALLOCATE or rebuild can make the change.

The addition of the CF to the active policy can be verified with the DISPLAY XCF,CF,CFNAME=cfname system command.
On all z/OS systems, configure CHPIDs online using theCONFIG CHPID(chpxx,chpyy,...),ONLINE system command.
The availability of the CF can be verified on all systems with the following system commands:
```
DISPLAY XCF,CF,CFNAME=cfname
DISPLAY M=CHP(chpxx,chpyy...)
DISPLAY CF
```
The new CF will not contain any structures. See "Using REALLOCATE or POPULATECF to relocate coupling facility structures" in Managing coupling facility resources for a description of how to move structures to their most preferred CFs after a CF has been added to the configuration.