3gb file taking up 20gb of space!
 

I understand that small files can't take up less space than the size of a block but this is just ridiculous. Just look at this:
https://cdn.anonfiles.com/1393125870675.png

Any explanation for the large size?

My file system is Extended 4.

sparse ?

This time... it isn't sparse files.

The CD is a compressed distribution of FreeBSD. When the files are decompressed for use they expand to about 20GB.

That's interesting. You'd think with it being compressed and all that it would say something like "File size: 20gb, Size on disk: 3gb" instead of the other way around. Since it in fact says "Size on disk: 20gb," does this just mean that it can potentially take up 20gb (via decompression) or is it in fact taking up 20gb of space, and if it is, why not just store that extra 17gb as "actual" data rather than metadata?

Do you have more information this?

It's probably just down to the file manager having strange wording. Why not run "ls -la" in the terminal and find out the real size of the file?

ls reported 2.4 gb. I guess pcmanfm is just being weird.

From this post on the Arch forums it seems to be a bug in pcmanfm:
https://bbs.archlinux.org/viewtopic.php?id=115516