Something

vmadmin@xstation:~$ du /var/log
4       /var/log/news
4192    /var/log/installer/cdebconf
4704    /var/log/installer
4       /var/log/sysstat
24      /var/log/gdm
4       /var/log/vmware/vmsd-xaction
256     /var/log/vmware
21176   /var/log
vmadmin@xstation:~$ 


vmadmin@xstation:~$ du / | sort -rn >/ tmp/ diskuseage
bash: /: Is a directory