Great source for deleting millions of files in a ubuntu directory when you get an error:
/bin/rm: Argument list too long.
Well, simply navigate to the directory with the problem and execute this:
ls -1 | wc -l && time find . -type f -delete
Apparently, ‘find’ can handle large number of files better than ‘rm’ and it even has a -delete feature!
I just deleted 3 million files using this method.
Special thanks to Deleting tons of files in Linux Argument list too long | SteveKamerman.com.