Aspects of the present invention provide a disk-to-disk-to-tape backup method and system responsive to a combined backup request to backup a dataset to a backup disk according to a disk backup schedule and then to backup the dataset from the backup disk to a backup tape according to a tape backup schedule. The combined backup method completes a backup of the dataset to the backup disk and then to a backup tape device in accordance with a resolved schedule that considers potential conflicts between the schedules. To restore, aspects of the invention receive a request to restore a backup of the dataset from a backup-tape and the resolved schedule derived from the tape backup schedule and the disk backup schedule. The restoration verifies that a backup tape holds the target dataset by matching a combined backup identifier from the request against a corresponding combined backup identifier held in storage.