How to do "du" on all files under a directory in linux?

This is what I tried:

[demo@ ~]# ll /usr/local/apache2/logs/|xargs |du -hm -
du: cannot access `-': No such file or directory

I want to see the amount of space each file occupies in m unit.

How to do it the correct way?

Answer

I'm assuming ll is an alias for ls -l, in which case what's wrong with

du -hm /usr/local/apache2/logs/*