I thought I'd seen almost anything when it comes to problematic filenames, under all kinds of different circumstances.
I was wrong.
Using rsync for years now to sync everything to everything, it failed on me today.
Rsync said "Everything fine. No deltas", but I like to use "kdiff3" for final checking.
Kdiff pointed out, that rsync had silently ignored all files that contained "problematic" characters in their filename, such as ":" (colon) or "?" (question mark).
I know that Windows filesystems can't handle these characters, but I was syncing from ext4 to zfs.
I'm a big fan of clean filenames, but I am surprised that rsync didn't complain at all. No error, no warning. Nothing.
[SOLUTION]
It was not rsync!
Rsync did everything as it should and all files were there.The quirks was, that I used kdiff3 comparison over smb/samba share.
And since Windows can't handle certain characters, Samba also doesn't.
What Samba does is that it displays the file under legacy 8.3 notation (uppercase), but with random characters as filenames. Very misleading.
Links:
http://unix.stackexchange.com/questions ... hange.com)