Rebuilding the Structure to Increase the Storage Capacity

You can rebuild the structure to increase capacity only if the CFRM policy that defines the structure allows for a larger size. If the structure is already the maximum size allowed by the CFRM policy, you must request that the system programmer modify the CFRM policy to allow a larger structure size and reactivate the modified policy.

If the active CFRM policy allows for a larger list structure, you can issue the IXLREBLD macro to rebuild the structure with a larger size. If you prefer to involve the operator, your application can issue a message to notify the operator that the structure needs to be rebuilt. The operator must issue the SETXCF START,REBUILD command to initiate structure rebuild. Rebuilding a keyed list structure allocated in a CFLEVEL=3 or higher coupling facility with a larger size results in the creation of additional EMCs, entries, and elements, depending on the values specified for the EMCSTGPCT and entry-to-element ratios.

Note: Duplexed structures cannot be rebuilt while they remain duplexed. If the structure is duplexed, duplexing will need to be stopped before the structure can be rebuilt. This can be done using the IXLREBLD macro or the SETXCF STOP,REBUILD command. If the CFRM active policy specifies DUPLEX(ENABLED) for the structure and IXLREBLD IGNOREDUPLEX=YES is not used, the system might immediately reduplex the structure after the completion of the stop processing. There might be a delay before reduplexing when only two coupling facilities are available for duplexing the structure. Reduplexing will occur immediately in configurations with three or more coupling facilities available for duplexing the structure.

To prevent the system from immediately reduplexing the structure or reduplexing the structure at a later time, change the DUPLEX specification for the structure to DUPLEX(ALLOWED) or DUPLEX(DISABLED). Change the DUPLEX setting for the structure in the CFRM policy to DUPLEX(ALLOWED) before stopping duplexing, or change the DUPLEX setting for the structure to DUPLEX(DISABLED), which will cause XCF to initiate the stop processing. Change the DUPLEX setting back to DUPLEX(ENABLED) when you no longer need to prevent the system from reduplexing.