Guidelines for coupling facility reconfiguration
- CFRM uses the CFRM couple data set (CDS) to maintain status data about the current use of CF resources in the sysplex. This status data is referred to as the CFRM active policy (or just active policy).
- Activating a CFRM policy initiates a transition to the policy
that might involve various changes to the CFRM active policy. The
changes might remain pending if CF resources are in use. Operator
intervention might be required to allow CFRM to make the pending policy
changes. Consider the following conditions:
- A CFRM policy contains CF definitions that associate a name with a CF (identified by a hardware node descriptor, partition, and CPCID). If a CF being used by the sysplex has a structure allocated in it, activating a policy that does not define the CF causes the CF definition to become pending deletion from the CFRM active policy. The CF will not be deleted from the active policy until all structures are removed from the CF.
- If a structure is allocated, activating a CFRM policy that does not define the structure causes the structure definition to become pending deletion from the CFRM active policy. The structure will not be deleted from the active policy until all instances of the structure are removed from coupling facilities in the active policy - this includes discontinuing use of the structure by the application.
- If a structure is allocated, activating a CFRM policy that would cause a change to the structure definition in the CFRM active policy may become pending. REALLOCATE or structure rebuild is needed to make pending structure changes in the active policy when the change cannot be made immediately.
- Adding/defining a CF to the configuration
- Removing/deleting a CF from the configuration
- CF maintenance
- CF hardware reconfiguration
For guidelines and a procedure to add or define a CF to the configuration, see Adding a Coupling Facility.
- Planning for a Coupling Facility Shutdown
- Removing a coupling facility from the configuration
If all coupling facilities are to be deleted from the configuration, see Transitioning from a Parallel Sysplex to a base sysplex instead.
- Adding a structure
- Deleting a structure from the CFRM active policy
If all structures are to be deleted from the configuration, see Transitioning from a Parallel Sysplex to a base sysplex instead.
- Replacing one CF with another CF
- Moving a CF from one CPC to another CPC
- Moving a CF from one PR/SM partition to another on the same CPC.
- When the reconfiguration involves replacing or moving all coupling facilities at the same time, follow instructions on Upgrading or replacing all coupling facilities.
- When multiple coupling facilities exist, follow the procedures
defined in Upgrading or replacing a coupling facility.
This might involve changing the I/O configuration to delete and re-add the CF from the I/O configuration. This will ensure configuration-sensitive products are synchronized with the reconfiguration.
Alternatively, based on the needs of the installation, the reconfiguration can be accomplished without affecting the I/O configuration. The existing I/O configuration can be "reused" as long as CHPID information for the CF has not changed as defined for the z/OS images. Similarly, the SNA address used for the new CF must be the same as the address used for the old CF.
- Alternatively, follow the procedures for Removing a coupling facility from the configuration, including deleting its definition from the I/O configuration for the affected z/OS image(s). Then follow the procedures for Adding a Coupling Facility to add the CF to the sysplex. This will ensure that sensitive products are synchronized with the reconfiguration.
- z/OS MVS System Commands
- z/OS HCD Planning
- z/OS HCD User's Guide
- PR/SM Planning Guide
- IOCP User's Guide