I have used fdupes for this with good success.
I had a lot of duplicate due to the fact that I stored multiple folders
keeping my handy pics and movies. This resulted in a waste of space.
Benefit of fdupes about other tools IMO: It also can process movies which
might be often part of camera specific content.
Disadvantage so far I found:
fdupes asks for any found duplicates for manual input. I found a trick to get
around this and only keep the first file:
yes 1 | fdupes -rd /*
Mind you that fdupes is a bit slower than other tools but I found it working
very nicely.
