Disc spanning

Disc spanning is a feature of CD and DVD burning software that automatically spreads a large amount of data across many data discs if the data set's size exceeds the storage capacity of an individual blank disc. The advantage is that the user does not need to split up files and directories into two or more (blank disc sized) pieces by hand. The software may or may not support slicing a single large file in order to span it but all disc spanners can divide numerous files that are smaller than one blank disc's capacity across many discs.

Disc spanning works well on CD media in many applications, but spanning on DVD media fails often. This lack of reliable DVD data disc spanning is odd, as disc spanning was used extensively on older 3.5" and 5.25" floppy discs. Most users assume every operating system can perform disc spanning on any media as a built in function; this is incorrect.

Some disc spanning schemes include a small program to reassemble the data set into the same structure it had on the source machine. This program could be written to the first disc only, or to every disc in the set.