With SP 5.2 and above and a structure allocated in a coupling facility with CFLEVEL=1 or higher, you can alter the size of the structure to increase capacity or the entry-to-element ratio to reapportion the structure's storage. As with the rebuild function, you can alter the structure only if the CFRM policy that defines the structure allows for a larger size. You can issue the IXLALTER macro or notify the operator to issue the SETXCF START,ALTER command to initiate structure alter.