Cloning volumes or save sets is beneficial for the following purposes:
If you use a filesystem as a storage device, clone your data to tape when the file-type volume fills with data. This action ensures that your data is available for recovery if your file-type volume fills quickly.
Create clones of your media to store identical copies of your data off-site, or share or transfer important data to other company facilities easily.
Most media has a limited lifespan. Consequently, routinely replace your volumes. The expiration date of a storage volume indicates how old the physical media is, not the data on the volume. A volume has a default expiration date of two years after it is labeled. If you relabel a volume, it receives a new two-year expiration date. When a volume reaches its expiration date, ISM automatically changes the Backup status of the volume to Disabled. This status means that no new data can be written to the volume. However, the data on the volume can still be recovered until the volume is relabeled. If you have old volumes that contain important data, clone them before they expire to ensure the safety of the data. If you clone a volume to newer media, you can prevent media failures during recover operations. You can determine the expiration date of your physical media with the ism_show -volumes command at the command line.
When you clone a volume, you can determine the integrity of backed-up data. ISM displays an error message if it has difficulty reading the data from the original volume during the cloning process.
You can clone entire volumes from the command line. Because save sets can span multiple volumes, ISM might request more than one source volume to complete the cloning operation. Furthermore, because media varies in size and capacity, you might need more destination volumes to hold the cloned data than the source volumes require. Conversely, depending on the type of media that you use, you might be able to fit multiple source volumes on one destination volume.