I have a few video DVDs that a "df -h" says:

/dev/dvd 8.0G 8.0G 0 100% /media/cdrom0

But a "right-click, properties" says just over 50GB for example. This means when I copy the data with a "copy, paste" or with something like dvdbackup, it copies over 50GB.

I think it must be a copy protection attempt. Some VOBs are identical (same md5sum) but with different names. I find if I copy the whole thing and delete the duplicates, then it doesn't play properly (can't find the files it needs).

Can anyone shed light on this?

Thanks

Seems like you have pretty much exactly the same issue as I do, except for me, instead of a dvd it is an NFS mounted filesystem (see post: NFS monted system size)... So I dont think it is anything to do with copy protection... anybody answering your question, or mine, will answer both.. or maybe not...

What exactly is telling you the exaggerated size? Where does this 'right click/properties' come from?

Any GUI file manager.