DP managed control file is an optional backup object. If such option is enabled, DP triggers this object backup when he receives a signal from RMAN/Oracle indicating that all the objects composing the database were backed up successfully. In this customer situation, the environment was so slow that such signal arrives after more than 30 minutes of Data Protector media agent inactivity. Data Protector by default assumes that after 10 minutes of media agent inactivity such agent can be stopped.
Solution is to increase the BackupDeviceIdle variable value to 1 hour.
However, such slow environment should be invetsigated and corrected as it may lead to other problems.