2. First steps

2.1 Logging in

Prerequisites for Windows Users

If you have a Microsoft Windows based machine in front of you, first of all you will need to install something called a terminal emulator on your PC to be able to login. (The terminal emulator is so called because it mimics the actions of an old style "dumb" terminal used to access UNIX systems - unfortunately UNIX still doesn't understand how to talk to a PC properly). There are a range of these available however, the one we will use here is called PuTTY (we'll cover a more advanced one called MobaXterm in a later section). If you are on a Managed Windows System PC, you can install this directly by clicking:

(Start) -> Install University Apps -> Internet -> PuTTY

or if you are off-campus, you can install it from the web at:


Using PuTTY on Windows

Once PuTTY has been installed, you should see a PuTTY icon appear on the desktop. Double-click on it to start a PuTTY "session" and the following Window should appear:

puty_grab (50K)

In the box marked "Host Name", enter chadwick.liv.ac.uk which is the full address of the chadwick cluster (strictly speaking only the chadwick part is needed if you are on campus). A terminal window as shown below should appear and you will now be prompted for your username and password. On chadwick, these will be the same as your MWS/email account.

terminal (12K)

Using a Mac or a Linux/UNIX machine

If you are using a Mac or a Linux (or other UNIX) based machine then there is no need to install a terminal emulator and you can login straight away using a built in program called ssh (secure shell). To do this, open a terminal window end enter the following command:

$ ssh -l your-username chadwick.liv.ac.uk

where your-username is your standard MWS username. You will then be prompted for your password which will be the same as for the MWS.

Access from off-campus

Accessing chadwick (and most local systems) from outside the campus firewall is slightly more difficult as direct conections are not allowed for security reasons. There are two ways around this - using Apps Anywhere or establishing a virtual private network (VPN) connection first. Details of how to install and use Apps Anywhere are available on the CSD website at:


Once you have logged in to Apps Anywhere, add PuTTY to your applications group (if necessary) and start the PuTTY app. You can then login as above. Incidently, if you see a security warning about an untrusted certificate pop up, just click on the "Yes" option.

If Apps Anywhere is not available, you can still login by establishing a virtual private network (VPN) connection first and then logging in as above. Details of how to use the VPN are available on the CSD website at:


2.2 Logging out

To logout of chadwick and finish your UNIX "session", use the following command:

$ exit

It is also possible to end your session by simply closing the terminal window however this is bad practise and should be avoided. You may read in some texts that it's also possible to logout by typing [Ctrl] and d together (i.e. [Ctrl-d]). This is also best avoided although it's something to be aware of in the unlikely case that you do it accidently.

2.3 Summary

2.5 Command summary

Command Meaning
exit end your UNIX session - i.e. logout