Note: public PCs with Linux are being eliminated
Math system user accounts moved to virtual server
This information concerns mainly the public PCs with Linux used in the department - most of them are in Lunt B10 and a few graduate offices.
To use the mathematics department computers you must have an account. One of the office staff can tell you how to do that. The first step is to fill out the new user application form (electronic format).
When you get an account, you will be assigned a `username'. For example, it might be your first name arnie or your initials arw, or your first initial and your last name separated by the character `_', a_weber. In addition, you will be assigned a temporary password which will be some bizarre string of characters. One of the first things you should do is to change your password.
In order to log on you must provide the computer your username and password. At the login window first type your login name, press the "enter" key, type your password and press the "enter" key. As a security measure your password will not appear on the screen. If everything goes OK the computer will start an X session. Now you can use the mouse and start any of various applications, or open a window (terminal). You can open a window by placing the mouse arrow on the background and clicking the right button (this opens a menu), then clicking in "New Terminal". Inside the window you should see a `prompt' which may look something like
If you are familiar with Unix/Linux you can now type any of a large collection of system commands. If interested see any tutorial on Unix such as:arnie@courant$
https://www.tutorialspoint.com/unix/
You can login remotely to the Math computer system by using ssh, e.g. from another machine with a Unix-like environment:
ssh <username>@lunt.math.northwestern.eduwhere <username> is your username. Note that in order to login to our system from outside the NU network you need to configure and start VPN:
http://www.it.northwestern.edu/oncampus/vpn/
The first thing you should do is to change your password to something secret which only you know. Choose something no one else can easily guess but which is easy for you to remember. It should be at least 8 characters.
Be careful when picking your password, many security attacks on computer systems take advantage of users choosing weak (easy to guess) passwords. Keep in mind that even if you believe you do not have anything valuable in your account, in fact you do have something of great value to attackers: a computer account that can be used to send spam and other kinds of malware, and to launch attacks against other systems.
The following are a few general guidelines on how to pick a strong password:
One possibility is to pick an easy to remember sentence and construct a password from parts of that sentence. For example, "SW&t7d's" stands for the phrase ``Snow White and the seven dwarfs''.
You shall not use any passwords that you used in other places, like the university NetID, or accounts on other universities (places).
More on strong passwords: strong-password.html
To change your password use the following electronic form:
https://sites.math.northwestern.edu/system/passwd.cgi
Given that our computer system is shared by many users and there is a limited disk space on our server, our system uses disk quotas limiting the amount of disk space a user is allowed to occupy. The current limitations for new accounts is 500MB for the home directory.
A user that surpasses his/her quota will receive a warning from the system and given a grace period (usually 7 days) to remove files from the home directory, or delete email messages (depending on where the quota has been exceeded).
Talk to your system administrator if because of special circumstances you need a larger quota.
Just as important as logging on is being able to log off again, so that the terminal is secure and available for someone else to use.
If you are using the Gnome desktop, open the menu of programs and applications, select "Log out" and click "yes" in the confirmation window. On Ubuntu click the gear sign in the upper right corner of the screen and select "Log Out..."
If you still can see the computer prompt that means that you have not logged off completely. Type exit or logout and you should see a login prompt similar to this:
The terminal is now ready for someone else to log on.courant login:
Note: Even if you have a "private" machine in your office that nobody else is going to use, it is important that you log off before you leave for the day or for a relatively long period of time (hours). Do not leave programs open and applications running unless really necessary. Nightly backups are better performed on machines under low activity (files cannot be properly backed up if the are modified during the backup process.) The machine will recover more easily after any temporary server problems if nobody is logged on it.