When a z/os dynamic I/O change is in progress, and CA Allocate is in its volume selection function for an allocation, there is a rare chance of an abend S0C4. SYMPTOMS: IEA995I SYMPTOM DUMP OUTPUT SYSTEM COMPLETION CODE=0C4 REASON CODE=00000004 DATA AT PSW xxxxxxxx - D2037000 40004177 00044144
Release: Component: ALLOC
ST03707 test apar has been written for this new defect. CIRCUMVENTION: Quiesce the z/os system before implementing the dynamic I/O change.