I use Lubuntu 16.04.1
after successfully copying the content (pdf files) of one folder to a new one (both on my external hard drive), I observed that most of the files duplicated in the original folder (same name, same size,...).
When I delete (or cut) one of the duplicated files, the remaining file with the same name turns corrupted, if I restore the dulplicated file it 'merges' with its duplicate without notification and then pdf file opens again without any problem.
I merged like that all duplicated files but when after some time I plugged again my external hard drive, I observed that all those pdf files were duplicated again !
The duplicated files are not corrupted, I can open both of them.
Could you help please ?
PS:I must say that I often use this external hard drive with Windows Vista (!) (dual-boot).