After a volume backup task has obtained a tape daily backup volume, it continues to use that volume until the volume is no longer needed, the volume becomes full, or certain error conditions occur.
If end-of-volume is reached while DFSMShsm is writing on a tape daily backup volume, DFSMShsm considers the currently mounted tape daily backup volume to be full and selects another tape volume.
A backup version of a data set can span more than one tape backup volume. DFSMShsm fails the backup of a data set if the data set spans more than 254 tape backup volumes.
When DFSMShsm reaches end-of-volume while writing on a tape daily backup volume, the processing that occurs depends on whether you want DFSMShsm to select a volume from tapes already known to it, or to select a scratch tape volume.
If DFSMShsm cannot find a volume that meets the criteria just specified or if you specified SETSYS SELECTVOLUME(SCRATCH) or SELECTVOLUME(BACKUP(SCRATCH)), DFSMShsm requests that a scratch tape be mounted on the already allocated unit. When the operator mounts a scratch tape, DFSMShsm assigns it as a tape daily backup volume and assigns it to the current day in the backup cycle.
After the operator mounts the volume, DFSMShsm continues backing up the current data set to that volume.