DFSMSrmm does not ensure that the volumes you use with BTLS in the automated tape library meet the z/OS labeling restrictions that apply for system-managed tape volumes. You must make sure that only z/OS standard label volumes with the same external and internal volume serial number are entered into the automated tape library. Failure to do so can result in incorrect processing by DFSMSrmm. For example, DFSMSrmm records the internal volume serial number of the mounted volume in the DFSMSrmm control data set, while BTLS uses the external volume serial number to request a mount.

When you migrate from BTLS management to system-managed tape, migration is easier if you use only z/OS standard label volumes. Also, under system-managed tape processing, DFSMSrmm ensures that the volume serial number and rack number match, rejecting volumes that do not meet this requirement. Considering these restrictions during BTLS implementation will make migration to system-managed tape easier.