Using mirror status verification to check for non-duplex volumes

Mirror status verification function checks for the presence of non-duplex volumes in the session. The function also checks duplex volumes for unexpected XRC device status in the primary storage subsystem. Exceptions are reported in system messages. Duplex volumes found to have unexpected device status are immediately suspended. You can specify the AUTO_READD flag to automatically readd the volumes.

The mirror status verification function is invoked under the following four circumstances: The mirror status verification function issues message ANTX8150I - ANTX8153I and might suspend volumes. See z/OS MVS System Messages, Vol 1 (ABA-AOM) for more information.
Mirror status verification exploits the recordset accumulator query capability of the primary storage subsystem, if available. To ensure that the data mover recognizes the capability and provides full verification function, issue the following command to each XRC session:
XQUERY session_id STO FEATURES
If a - is displayed, contact your hardware support representative for information on upgrading microcode to a level that supports write pacing.