If you need to check Usage, but you wish to avoid the mount-point, you can use the command
[root@hpc-hn /]# du -h -x -d 1
48M ./etc
552M ./root
11G ./var
1.1G ./tmp
11G ./usr
0 ./media
0 ./mnt
4.8G ./opt
0 ./srv
0 ./install
0 ./log
0 ./misc
0 ./net
0 ./server_priv
0 ./ProjectSpace
0 ./media1
0 ./media2
28G .
- -h refers to human-readable
- -d refers to depth level. By default, it is 0 which is the same as summarize
- -x skip directories on different file systems