Quoting Raymond Norton <admin at lctn.org>:

> When I ssh to one of our servers as a normal user and su to root, none of
> the root commands will work; ifconfig, service xx start, etc.. The shell
> indicates ifconfig and service cannot be found. Whoami shows I am logged
> in as root??
> 
> 
> Raymond
> 

Doing a simple su does not change your path, so things normally available to
root will not be found. Do an su - to get root's environment variables.

Elevates privlieges but still uses your environment:
$ su
Elevates privileges and uses root's environment:
$ su -

Josh