debian3164lamp:~# uname -a
Linux debian3164lamp 2.6.8-12-amd64-k8-smp #1 SMP Tue Sep 19 01:04:26 UTC 2006 x86_64 GNU/Linux
debian3164lamp:~# mount
/dev/sda2 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
usbfs on /proc/bus/usb type usbfs (rw)
/dev/sdb1 on /backup type xfs (rw)
debian3164lamp:~# mkdir /usr/sbin/bla
mkdir: cannot create directory `/usr/sbin/bla': Permission denied
debian3164lamp:~# mkdir /opt/bla
debian3164lamp:~# whoami 
root
debian3164lamp:~#