Size on my internal drive and external hard drive

[Smiggy]

Hello,

I'm new here and I was wondering if someone can be kind enough to help me work a small problem out.

I have an internal hard that's 29.1TB in capacity. It's been filled and there is 938GB remaining.

I also have my stuff backed up on 3 external hard drives (Seagate) making up the size overall size (6TB, 8TB and 16TB). The space remaining across the 3 drives is 933.8GB.

There is a discrepancy of 4.2GB. I'm not the one who likes wasting space because all these drives were expensive. I've checked internal and external drives for any duplicate files, I've run duplicate apps to check this and it came with nothing.

I checked if there were the same number of files on both the internal and external hard drives, there is, but I discovered much of this were tiny hidden files.

A friend of mine suggested, the external hard drives may have used up more space to store all my data because the way it writes data is different to an SSD. What do you guys think? Does this sound plausible? Or do you have any ideas how I can trace this menace of a file down?

Thank you for your time.

[Lardman]

You must have a very large homework folder. Have a Google about filesystem overheads.