Automatic recall

If a data set that has migrated is needed for processing, DFSMShsm recalls the data set from the migration volume on which it resides to an SMS-managed volume. The storage management subsystem selects the SMS-managed volume to which the data set is returned. Migrated extended format VSAM data sets can be recalled only as extended format VSAM data sets. Migrated extended format sequential access method (SAM) data sets can be recalled as extended format or nonextended format data sets.

If a data set is assigned to a management class with no defined transition, then the allocation will be performed using the standard ACS routines.

If a data set is assigned to a management class with a defined transition, then the allocation will be done as follows:

If the data set has not yet transitioned nor missed a transition, then the allocation will be performed using the standard ACS routines.
If the data set had transitioned before being migrated, then the allocation will be performed using the class transition ACS routines to ensure that the data set is allocated back to the appropriate level.
If the data set missed one or more transitions during the period in which it was migrated, then the allocation will be performed using the class transition ACS routines. If multiple transitions were missed, then the class transition ACS routines will be invoked for each transition that was missed (up to 5 times), to ensure that the data set is allocated on the appropriate level.

Note: To avoid circularity, DFSMShsm will limit the number of repeated ACS routine invocations to five.