Introduction to the GNU/Linux environment at D-ITET for new GNU/Linux users

Usage Policy

ETH provides a use policy of IT resources. Please read it and follow these rules.

The most important points are:

• You may not abuse the computer equipment for illegal activities (spam, hacking etc.)
• Viewing and providing offfensive, abusive and illegal material is prohibited (hate speech, racism, pornography etc.)
• Sharing copyrighted material is prohibited

Deutsche Version: http://www.rechtssammlung.ethz.ch/pdf/203.21_BOTfinal-2005.pdf

English version: http://www.rechtssammlung.ethz.ch/pdf/203.21_BOTfinal-2005_Engl.pdf

Is this introduction for me?

This introduction is for people who start to work on a computer running Debian GNU/Linux which is managed by ISG.EE. While this introduction is directed to GNU/Linux beginners, you might also find some useful information if you are already an experienced GNU/Linux user.

The operating system

First let us clarify some terms. You surely already have heard of "Linux." This denotes the kernel of an operating system, being responsible for making hardware devices and resources available to applications and libraries. On top of the Linux kernel, there is a lot of software, that makes the operating system friendly to use. This software on top of the Linux kernel is from a project called "GNU," which is a recursive acronym for "GNU's Not Unix."

In common usage these terms are somewhat ambiguous. Most of the time when people talk about Linux they mean in fact an operating system consisting of the Linux kernel with GNU software.

Now all the source code of the Linux kernel and of any GNU software can be used, freely modified, and redistributed by anyone under the terms of the GNU General Public License (GNU GPL). Many projects and companies took this opportunity to design their own custom package of Linux and GNU software. That is the reason why there are so many distributions of GNU/Linux around. The most popular being Ubuntu, openSUSE, Fedora, and Debian.

Debian GNU/Linux is a non commercial operating system developed by over one thousand volunteers around the world. It is well known for its stability and its huge software repositories. These are some of the reasons why Debian GNU/Linux is being used on the GNU/Linux systems managed by ISG.EE. However, Debian is also rather targeted towards experienced users. At least when it comes to installation and configuration of the operating system. That is why we recommend Ubuntu to you, if you want to install GNU/Linux on your own laptop or on your computer at home.

Window Mangers and Desktop Environments

You are probably already logged in now, in order to read this. Never mind. Then just try to remember this the next time you log in. In the login dialog you will notice a button called Session in the top left corner of the window. This is where you choose the window manager or desktop environment you want to use.

A window manager is just responsible for the look and feel of windows. The difference between some window managers is the way windows are decorated and how you interact with the graphical interface.

Desktop environments on the other hand incorporate a window manager plus a complete package of graphical applications that make their usage more comfortable. The most prominent examples of desktop environments are GNOME and KDE. By default, GNOME will be used on Debian/GNU Linux. Thus, if you did not change anything during log-in, you will now be working with GNOME. If you don't like it, log out and choose KDE. If you do not want to use GNOME or KDE it might be useful to have some command line knowledge and read some manuals on the usage of the corresponding window manager. Otherwise your work performance might be rather limited. If you ever happen to choose the window manager evilwm and wonder why nothing happens, just press CONTROL-ALT-ENTER, enter the command pkill -u $USER -f /usr/bin/evilwm, press ENTER and only come back to evilwm as soon as you have read its documentation.

We recommend that you use GNOME or KDE. For the sake of simplicity for this introduction we assume that you are running GNOME.

Your passwords

As a member of D-ITET you have got at least two passwords. The D-ITET and the NETHZ password. Below you can find a list of services provided.

You can (and should) change the passwords yourself. If for some reasons changing the passwords does not work, please come by in our office at ETL F 22, where we can help you. Do not forget to bring some identification. Unfortunately, we are not allowed to change passwords when you just call.

D-ITET password

• Student computers in ETZ D 96 and D 61
• ISG.EE managed computers in your institute
• Access to your network drive from home

You can change your D-ITET password on this website: https://apps.ee.ethz.ch/cligui/

You should always set your password by yourself and not keep the one given to you by a postwoman/postman or some IT support group (however friendly they might be or not )

Links

NETHZ password

• Student computers in the ETH main building (HG)
• ETHZ mail account
• WLAN
• VPN
• IDES

You can change your NETHZ password on this website: https://password.ethz.ch/

You should always set your password by yourself and not keep the one given to you by a postwoman/postman or some IT support group (however friendly they might be or not )

Links

Where to put your data

You probably want to make yourself a bit familiar with your operating system before going on. Let us first browse the filesystem a bit to see, what is important for you to know. If you are running the GNOME desktop environment, you will find the Computer symbol somewhere on the desktop. You can simply double-click it to see its contents. Now go to Computer > Filesystem. There are quite a lot of folders in there. But we will only look at folders which are probably most important for you. These are /scratch and /home (you won't see the "/" in the directory names; The "/" just denotes the "root" of the filesystem and comes in handy as soon as you start using the command line).

Within /home you will find at least one directory called after your username, e.g. /home/pmuster. This is a network folder, meaning that its data are physically stored on the departments storage server. This makes your home directory /home/pmuster (or however your home-folder is called) the most important place to store your date due to several reasons:

• Any data you put in here will be available on any other computer managed by us.
• Data is stored in a redundant manner on the storage server, reducing the danger of losing data due to hardware failures by several orders of magnitude (compared to data stored locally on one harddisk).
• The data is being backed up every night. Should you ever need a backup of some accidentally deleted files, just contact "support AT ee.ethz.ch." But bear in mind: There are no backups of files you created on the same day.
• You can easily access your home directory from your own laptop or computer at home (independent of the operating system you run there).

Now, redundancy, security, accessibility and backup strategies are not completely free of charge. That makes disk space on your home directory a very valuable entity. So valuable in fact, that we have to limit the maximally usable disk space in each home directory (called "quota"). In order to check your quota limit, issue the command quotack in a terminal (read the section "The command line" in order to get to know how to do this).

If you want to burn some ISO image you found on the web, or store some huge simulation data, you will soon notice, that the quota on you home directory will not be sufficient. That is where /scratch comes to rescue. Everyone has the permission to create and store files and folders in /scratch. There is no such thing as quota in there, and usually there are gigabytes of data free to use. Additionally, as /scratch is stored locally, you bypass the network bottleneck. Just remember that /scratch does not have any of the advantages of the home directory. If the harddrive of the computer you are working on crashes, your data in /scratch is lost while your data in the home directory are as save as ever. So please remember the following: Never put any important data in /scratch which you cannot regenerate by yourself.

Links

Applications

A lot of applications are available from the Applications panel on the top bar. We will mention just some few programs which could be of interest to you:

Many more programs such as Matlab are installed but cannot be started via the Applications menu. Open a terminal, type matlab and press ENTER to start the program.

Links

Email

As a member of D-ITET you have two accounts as explained above: The NETHZ account from the central IT services of ETH and the D-ITET account of the department. Likewise, you are accessible through two email addresses. Our example student Peter Muster with username pmuster will be accessible through pmuster@student.ethz.ch and pmuster@ee.ethz.ch. Nevertheless, if you are a new member at D-ITET, all your emails will arrive in the same mailbox, as mail to pmuster@ee.ethz.ch will automatically be forwarded to pmuster@student.ethz.ch.

The central mail server of ETH allows you to access your mails through

• a web interface,
• the IMAP standard,
• the MAPI standard (only with Microsoft Outlook).

For information how to configure your mail client (e.g. Thunderbird) please see the link to the corresponding documentation below.

Links

Printing

The central IT services of ETH maintain a service called VPP. With that you can print independent of your operating system almost anywhere at ETH. On most printers you will have to confirm your print job on a printer release station (next to the printer where you want to print).

In order to make printing easier for you, we have created an additional layer above VPP. With that, you can print directly through the common print dialog found in most applications. Just be sure to pick the right printer. The list of printers and where they are located can be found on the VPP homepage.

Links

Log out

GNU/Linux is a true multiuser operating system. Thus you should never shut down a student workstation by yourself. So if you are finished with your work for today, just log out. If you are using the GNOME desktop environment you do this e.g. through Desktop > Log out ...