A recent issue where trying to copy a 10GB file to an external disk raised an error “Not enough space” even though there was plenty. Files up to 1.5 GB copied fine but this one refused to go anywhere. Given a short window to get a copy of this file I used a utility to split the large file into 1GB chunks for reassembly later. The utility in question is HJSPLIT which you can get here. This fab little tool allows splitting at the command line and from pretty much every OS you could use. Its also multi platform compatible ie. Split on a Windows XP and Join together on a MAC.
If you are working with large files and need to do some file wrangling – this is definitely one for the toolbox.
With regard to the “error” – the disk in question is a specialist wireless external disk and I suspect compatibility issues between the xp host that I am copying the files from and this newer technology.