Manually splitting large disks
You may happen to run into the problem of having to back up more data than will fit onto a single tape, like when you have partitions that are much larger as a tape. Over time, the partition will hold more and more data, and when you started with a simple amanda configuration that backs up the partition as a whole, backups will fail sooner or later.
Thus, the need arises to virtually split partitions into parts so that each part remains smaller than a tape. One way to do that is creating appropriate entries in the disk list.