Explanation: CLASSTRANSITIONS is an optional parameter that specifies settings for class transitions during interval migration and on-demand migration windows. The EVENTDRIVENMIGRATION subparameter, when set to Y (YES, the default), indicates that data sets will be class transitioned during event-driven migration. A setting of N (NO) indicates that class transitions will not occur during event-driven migration processing and only occur during primary space management.
The SERIALIZATIONEXITS subparameter, when set to Y (YES) indicates that the user data set serialization error exits will be used during event driven migration. A setting of N (NO, the default) indicates that the user data set serialization error exits will not be used during event-driven migration.
SMS relationship: This keyword only applies to SMS managed volumes.
SETSYS default: Same as DFSMShsm default.
DFSMShsm default: If you do not specify this parameter on any SETSYS command, class transitions will be performed during event-driven migration, but user data set serialization error exits will not be used.