Coupling facility storage shortages

VTAM® monitors the total amount of storage used by a coupling facility structure, the number of entries in use, and the number of elements in use. If VTAM detects storage 80 percent used (or greater), VTAM will issue message IST1439I, which indicates which type of storage shortage has occurred. The shortage situation is not ended until the constrained resource reaches 70 percent utilization.

To correct constrained resources:

For total storage problems, change the SIZE parameter on the structure definition in the CFRM policy and issue a structure rebuild.
For entries and element problems, VTAM performs a structure rebuild to adjust the entry-to-element ratio at 100 percent utilization.