$ sudo du / -h --max-depth=1
16K	/lost+found
du: cannot access ‘/proc/28588/task/28588/fd/3’: No such file or directory
du: cannot access ‘/proc/28588/task/28588/fdinfo/3’: No such file or directory
du: cannot access ‘/proc/28588/fd/4’: No such file or directory
du: cannot access ‘/proc/28588/fdinfo/4’: No such file or directory
0	/proc
142M	/lib
0	/sys
7.4M	/bin
507M	/usr
4.0K	/media
4.0K	/srv
0	/dev
24K	/tmp
16K	/root
92M	/home
40M	/opt
25M	/run
3.7M	/etc
7.0M	/sbin
20M	/boot
232M	/var
4.0K	/mnt
1.1G	/