The reason you can't run the commands when you `su` to root is that they are not in your $PATH.
There are a couple solutions. I'll use `ifconfig` as an example.
will give you:
"bash: ifconfig: command not found"
will run ifconfig. The "-" means to read in root's environment variables, which adds /sbin to the path.
This will also run ifconfig, since an absolute PATH is specified.
Another approach would be to add /sbin & /usr/sbin to your own PATH.
vi .bashrc (or whatever editor you use). Add the line:
Once you log out and back in, these will be your settings, so you won't run into command not found when you run stuff in /sbin & /usr/sbin