What is DiskSpan?
DiskSpan is a CLS module created by Razor12911 initially to replace UltraArc. It has a big advantage compared with UltraArc but also a disadvantage.
DiskSpan is not a GUI program like UltraArc. It has to be called from cmd/batch. The big advantage compared with UltraArc is, that DiskSpan doesn't have to merge splitted archives back to a single original archive. It is the same principle as a splitted WinRAR / 7zip archive. In UltraArc, splitted archives have to be merged back to original archive before extraction starts, which is - depending on the size - time consuming. In some cases it could double the installation time and even double the installation size temporaly. The only disadvantage with DiskSpan compared to UltraArc is, that it doesn't support masked data compression.
How to use DiskSpan
There are two different ways on how to use DiskSpan. In _Tools archive in the CIU thread you will find two different versions. One is located inside UltraArc folder, the other, more complex but highly customizable version you will find in DiskSpan folder along with some examples.