Introduction to the Linux environment at D-ITET for new Linux users
IT infrastructure usage policy
ETH provides a usage policy (BOT: Benutzungsordnung für Telematik) 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
Here you find the most important BOT-relevant documents of Informatikdienste (ID):
Is this introduction for me?
This introduction is for people who start to work on a computer running Debian Linux which is managed by ISG.EE. While this introduction is directed to Linux beginners, you might also find some useful information if you are already an experienced Linux user.
The Linux 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 Linux around. The most popular being Ubuntu, openSUSE, Fedora, and Debian.
Debian 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 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 Linux on your own laptop or on your computer at home.
Window managers 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. After you entered the username you have the choice of several window managers or desktop environments at the bottom of the screen (by default this is set to System Default which is GNOME in the case of Debian Linux).
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 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.
For the sake of simplicity for this introduction we assume that you are running GNOME.
Our managed Linux clients authenticate against the ID nethz account service so you can change your password in the IAM Web Center
You should always set an own password and not keep the one sent to you in a letter or in an e-mail sent by some IT support group
- If for some reason changing the passwords does not work, please visit our support helpdesk in the office ETF D 106, where we can help you. Do not forget to bring an identification document (passport and so on).
- IT services provided by D-ITET
- Student computers in ETZ D 61.1, ETZ D 61.2, ETZ D 96.
- ISG.EE managed computers in your institute.
- Access to your network drive from home.
- IT services provided by the Informatikdienste (ID)
- Student computers in the ETH main building (HG)
- ETHZ mail account
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 > File System. 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.
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.
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:
Internet -> Firefox Web Browser (SEPP)
Internet -> Thunderbird Mail/News (SEPP)
Office -> OpenOffice.org Writer etc.
Office suite which can open all MS Office documents
Graphics -> GNU Image Manipulation Program
Image manipulation software with the same capabilities as Photoshop
Sound & Video -> VLC media player
Media Player for listening to music or watching videos
Accessories -> Terminal
Terminal (console) for the command line interface to the Linux operating system
Many more programs such as Matlab are installed but cannot be started via the Applications menu. To start them, open a terminal and type:
$ matlab // or matlab <TAB> <TAB> if you want to see which versions are available
and press ENTER to start the program.
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 firstname.lastname@example.org and email@example.com. Nevertheless, if you are a new member at D-ITET, all your emails will arrive in the same mailbox, as mail to firstname.lastname@example.org will automatically be forwarded to email@example.com.
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.
Public Linux workstations at D-ITET use the CUPS software (Common Unix Printing System) that is running on each client on localhost, TCP port 631. Applications supporting CUPS (most modern Linux GUI applications do so), read the CUPS_SERVER environment variable to communicate with the CUPS software (e.g. to query the list of all available printers). Printing jobs sent to the CUPS will be forwarded to the central IT services which is in charge of the printer infrastructure.
Have a look at the links below.
You might have to access a computer from a remote location. Remote Access allows you to work offsite while still having access to a distant computer. For more details, read the RemoteAccess article
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 System > Log out pmuster...