I have a 7gb .iso file, and I want to move it to a secondary HDD I have connected on my computer, first I tried to move the entire file and it failed saying the file was too large. I noticed always 4GB was copied, so I used split to generate 3GB chunks.

Now I have the 3 chunks in the secondary disk, and I am trying to join them using cat with:

cat x0* > backup.iso

But it also fails saying:

cat: write error: File too large

The resulting file is once again 4GB. How can I join these files?

I have plenty of space on that disk for the files (>50GB). I read somewhere that I should pipe the files contents in real time to avoid this error but I have no idea how to do it.