i am quite certain you can find the answer to your question in at least one of the 2011 questions on SF, via google, via reading the manual or similiar approaches without having to wait for someone to answer.
This question has been cross-posted on U&L here. Since the OP did not give an OS, the answer on SF is, perforce, kinda generic. The U&L one gives a few more details. Do you all agree with closing yours?
@terdon I don't have enough time! plus, the questions that are really interesting in U&L are ones that people like Stephane and Gilles answer much better than I can anyway...
@JennyD Yeah, tell me about it. There's still quite a bit of admin stuff though, and you're probably better at those. Gilles and Stephane are *nix gurus but not sysadmins as such.
yeah... I do look in but usually only at the front page, so if there happens to be a more sysadminny question there I'll pick it up - I just don't have the time to go search for them