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University of Helsinki Department of Computer Science
 

Department of Computer Science

The Computer System at the Department of Computer Science

Rooms and Appliances

The workstations at the Department of Computer Science can be found in rooms B121, B221, BK107, CK110, DK108 and DK110. You may use any computer in a computer classroom, unless teaching has been scheduled in the room.

The operating system of each workstation in the computer classrooms is Linux, and some computers run Microsoft Windows XP Pro, as well. The operating system can be changed as follows:

To shut down the currently running operating system

  • In Windows, press Ctrl-Alt-Del, click "Shutdown" and choose "Restart the computer"
  • In Linux, press Alt-W and choose Yes

Choose the operating system you want to use from the startup menu (Linux is the default).

Information on the computer classroom facilities: /compfac/ohjeet/Kokoonpanot/.

The Computer Science Department has several servers of its own, some of which can be used interactively, such as melkki.cs.helsinki.fi and melkinpaasi.cs.helsinki.fi. They can be contacted through ssh with the command ssh melkinpaasi.cs.helsinki.fi.

Linux

The Linux system makes a difference between upper and lower case letters in the password. You can get a terminal window for input of the commands by choosing from the toolbar the icon that has a picture of a seashell on it. The working session is ended by pressing the "Logout" from the K-menu at the bottom of the screen. The most popular programs can be found in and opened from this toolbar.

Windows

Your user account in the department's Windows system will not be activated until you have changed your password in Linux.

The same username and password are used in Windows as in Linux. The password cannot be changed in Windows, but has to be changed in Linux.

In the computer classes, the Linux home directory is shown as disk drive H in Windows.

Passwords

In Linux, the password can be changed with the command passwd. A good password has 7 - 8 digits (but no longer), containing upper and lower case letters as well as numbers and special characters. It should not be a word in any language, since programs decoding passwords use a wide range of dictionaries and know how to combine words, as well as recognizing words written backwards. To name an example, "car9doog" is not a good password! Names, social security numbers and special leisure activity terms are the worst passwords. However, you should be able to remember your password without having it written down on a piece of paper. You should no use the "Save password" service offered on the Web to save passwords from the university computer systems. This is prohibited in the rules for use of the university computer systems, section VI.4.
Please remember that a single user may endanger the security of the whole system with an inferior password.

Keep your password SECRET! Do not "lend" your password to anyone; you are responsible for EVERYTHING that has been done with your account.

The changed password is propagated to all computers of the department within the next 15 minutes, except for the mailserver, which is updated nightly.

Please remember to change your password at least every 6 months.

E-mail

In the Computer Science Department's system, e-mail addresses take the form Firstname.Surname@cs.helsinki.fi.
At the IT Department, they take the form Firstname.Surname@helsinki.fi.

The university is large, and it cannot be avoided that there will sometimes be several people with the same name. Their addresses are usually distinguished from each other by inserting the first letter of a second name between first name and surname. The addresses given by the IT Department and the CS Dept. may be different, so you should not try to guess e-mail addresses.

You will find the department's e-mail addresses on the department's Web pages. With the command lupa, anyone can check their own e-mail address in the CS Dept. system.

Co-use of the IT Department's Unix System

Students with computer science as their major subject have two user accounts; one for the department's own system, the other for the IT Department's cc-unix servers. Kruuna, sirppi, myntti and vesuri.helsinki.fi are names of some of the IT Department's servers.

Once the IT Department cc-unix account expires, the CS Department account will expire also. Therefore, renewing the cc account keeps the cs account also alive.

There is a separate e-mail address, home directory and password for each account. The user is identified as the same by a username that is the same in both systems.

When the user account is activated, you will have the same password in both systems. It has to be changed separately in the CS Dept.'s and the IT Department's systems.

It is possible to reach the home directory in the CS Dept. system from the IT Dept.'s Unixes. The path to the Computer Science Department's directory is /home/fs-x/y/username (x and y are the same as on your home directory at the CS Department's system).

You can redirect the e-mail from the IT Department to the Department of Computer Science by creating the file .forward in your IT Dept. home directory. The file should only contain the forwarding address, e.g. Firstname.Surname@cs.helsinki.fi.

In order to ensure that the forwarding will succeed, give the command

chmod a+r .forward

Mail from the IT Department can also be directed by a web form, please see http://www.helsinki.fi/atk/english/mappi/misc.html.

Additional Information

support@cs.helsinki.fi

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