WAIT | NOWAIT are mutually exclusive, optional parameters that specify whether you want to wait for the HMIGRATE command to complete.

WAIT specifies that you want to wait for the HMIGRATE command to complete. When DFSMShsm successfully completes the HMIGRATE process, an ARC1000I message is issued. If the HMIGRATE process does not complete successfully, an ARC1001I message is issued. If you press the TSO Attention key before DFSMShsm completes the command, DFSMShsm issues an ARC1800I message and does not issue an ARC1000I message.

NOWAIT specifies that you do not want to wait for the HMIGRATE command to complete. When DFSMShsm successfully receives the request, an ARC1007I message is issued. After DFSMShsm successfully completes the HMIGRATE command, an ARC1000I message is issued. If the HMIGRATE command does not complete successfully, an ARC1001I message is issued.