SETXCF START,POLICY is the command used to activate an administrative policy. If no current active policy is available, the activation takes effect immediately. If a transition to the newly activated policy is required, this command causes the following to occur over time in the active policy.

• When adding a new coupling facility, the logical name of the coupling facility is updated in all the preference lists of the structure definitions in the active policy. There might be a delay while all systems complete the update before an operator can use the new logical name. Once all systems recognize the new coupling facility logical name, the operator can use the name on all commands referencing the coupling facility.
• When changing the dump space size, the size of the coupling facility dump space is updated in the CFRM active policy immediately. However, the actual size of the dump space at any given time is determined by:
  • The size specified in the policy
  • The amount of space assigned to a dump in the dump space
  • The total amount of space available in the coupling facility.

  MVS™ attempts to satisfy requests to change the dump space size immediately and if not successful, continues to attempt the change. Use the DISPLAY CF command to determine the policy size and the actual size of the dump space in the coupling facility.

• When deleting or modifying a structure or coupling facility definition, the policy transition proceeds as follows. Note that the system handles a modification to a structure or coupling facility definition as an implicit “delete and add”.
  • The change takes effect immediately if coupling facility resources are not allocated for the particular structure.
  • Changes to some parameters (such as DUPLEX, FULLTHRESHOLD, or ALLOWAUTOALT) take effect immediately.
  • The change remains pending if coupling facility resources are allocated either for the structure or for any structures in the coupling facility being modified. The structure's resources need to be deallocated in order for the pending policy change to take effect. Rebuilding the structure is the preferred method of accomplishing this, if the structure allows rebuild. The operator command SETXCF START,REBUILD can be used to rebuild the structure in either the same coupling facility or in another coupling facility. In some cases it might be necessary to deallocate the structure using the SETXCF FORCE command, but that is not the preferred method.

    The DISPLAY XCF command provides specific information about a structure and any pending policy changes.

• When releasing coupling facility resources, the following order should be observed:
  1. Remove all connections to an allocated structure.

     The connection removal should be initiated by the application using the connection and should result in no active connections to the structure. However, operator intervention might be required to remove failed-persistent connections. Use the DISPLAY XCF,STR command to determine which connections are in a failed-persistent state and then delete each connection using the SETXCF FORCE command.

  2. Remove the allocated structure from the coupling facility.

     The system deletes a non-persistent structure once all connections to the structure are removed. The operator can remove a persistent structure by using the SETXCF FORCE,STRUCTURE command. Note that if the structure has an associated structure dump, then the operator must issue SETXCF FORCE,STRDUMP before deleting the structure.

• The addition of a coupling facility or structure takes effect immediately, assuming that all resources from the prior active policy have been released. The CFRM couple data set is formatted to contain a fixed number of coupling facility and structure definitions in the active policy. If deletions or modifications of prior coupling facilities or deletions of structures are still pending, then additions might also become pending.