You can use different ways to establish or suspend a dual pair (for example, using IDCAMS for MVS or the DUPLEX command for VM). When you are establishing or suspending a dual pair, ICKDSF is unable to ensure the volume is in a usable state. You must allow the current ICKDSF command to run to its completion before changing the primary or secondary volume state (establishing or suspending a dual pair). Also, do not start ICKDSF until a dual volume change has completed. If an ICKDSF command function prematurely ends, examine the ICKDSF output carefully to determine the reason before you reissue the function. If the volume has changed from a duplex state to a suspended duplex state, the original primary and secondary may be swapped. Be sure you are reissuing ICKDSF to the correct volume. After you determine if it is the primary or the secondary having the problem, you can use the DIRECTIO parameter to issue the command to a secondary of the duplex pair.