In an approach to automatically reconciling data in HSM without affecting system performance, responsive to migrating a file on a hierarchical storage system from a primary storage to one or more tape drives, one or more file migration records are recorded in a reconcile database. Responsive to the occurrence of a file event on the primary storage, the one or more file migration records in the reconcile database are updated. Responsive to receiving a command to unmount a first mounted tape on one of the one or more tape drives, a reconcile function is performed on the first mounted tape, wherein the reconcile function updates the first mounted tape with the one or more file migration records in the reconcile database.