TDMF ownership of target volume

TDMF "owns" the target volume during the life of the migration session to preserve physical data integrity. Except for a few non-disruptive inquiries, any I/O operation to the target volume by anything other than TDMF is rejected. Also, a message is created with IOSB completion code X’4A’ (the I/O was prevented). The message might be IOS000I or some other MVS message that indicates an error by the application or MVS system component