With fast subsequent migration, data sets recalled from ML2 tape (but not changed, recreated or backed up) can be reconnected to the original ML2 tape. This eliminates unnecessary data movement resulting from remigration and reduces the need to recycle these tapes. Reconnection can occur during individual data set migration or during volume migration. Both SMS and non-SMS data sets are supported; however, reconnection is only supported in a SETSYS USERDATASETSERIALIZATION environment and the fast subsequent migration function will not occur for Hierarchical File System (HFS) data sets.

Note: DFSMShsm performs fast subsequent migration only if the data set has not changed since recall. DFSMShsm determines this based on flags in the Format 1 DSCB that are set when the data set is recalled. This allows DFSMShsm to be compatible with other backup applications as DFSMShsm no longer relies on the change bit in the Format 1 DSCB, which may be set or reset by other data set backup products.