If the user specifies both volume and unit information during allocation of a non-SMS-managed volume or if the allocation process is not done, a migrated data set will still be on a migration volume when the open routine tries to open the data set. When the non-VSAM open routine does not find the data set VTOC entry for a non-VSAM data set, DFSMShsm intercepts the abnormal end and tries to recall the data set. Enough space must exist for DFSMShsm to recall the data set to the volume the open routine specifies. Otherwise, the recall fails and the open routine abnormally ends.
If a user allocates an uncataloged data set and mistakenly specifies the wrong volume, the user receives a VTOC entry-not-found abnormal end. However, if a migrated data set exists with the same data set name as the data set the user is allocating, DFSMShsm can recall the migrated data set to a user’s volume. The user might be able to open the data set, if it is unprotected, even though it could belong to someone else.