In order to obtain access to the cluster you need to do two things: firstly, you need to register your account for cluster usage and secondly you need to set up a Secure Shell (ssh) connection. On this page the first part is described, details about SSH connections can be found here.

You log in on the cluster with your ZIMT user ID (formerly called “g-number”) and password, provided cluster usage is enabled for your ID as described below. You can also change the password of your ZIMT ID via the cluster.

Note: Since May 2020, access with your password is only possible from inside the university network or Uni VPN. More details here.

Obtaining access: employees

University employees can request cluster access themselves. To do that you need to do the following:

  1. Log in to the Nutzerkontenverwaltung with your ZIMT ID.
  2. Click on “Meine Optionen”.
  3. Select the option “Ressourcen zum Wissenschaftlichen Rechnen (OMNI)” via the Button “Jetzt buchen”.
  4. Enter the requested information and agree to the Terms of Use (link in German).
  5. Your application will normally be processed within a few days. You will receive an email “Welcome to the Cluster” which will give further details.

Obtaining access: students

Students can only use the cluster if they have an employee as a supervisor. That supervisor has to have cluster access already. Cluster access for students is limited to one year, but may be extended an arbitrary number of times and at any point, by one year each. The extension can also be performed by a different employee than the supervisor.

Adding a student as a supervisor

As a supervisor, you can add access for your students yourself in the Nutzerkontenverwaltung (Unisim). You only need the student’s e-mail address.

To add a student, you need to do the following:

  1. Log into the Nutzerkontenverwaltung using your own ZIMT ID.
  2. On the left-hand side, click on “Meine Optionen”.
  3. At the bottom of the “Meine Optionen” page you can find “Freigabe von ggf. kostenpflichtigen Optionen für Dritte” (unlocking paid and unpaid options for another person).
  4. Select “Ressourcen zum Wissenschaftlichen Rechnen (OMNI) für Studenten/Mitarbeiter” via the button “Zur Eingabe”.
  5. On the next screen, add one or more students or employees using their e-mail addresses
  6. These persons will receive an invitation e-mail with a link to the option in the Nutzerkontenverwaltung. There, each person needs to enter the required information and agree to the Terms of Use (link in German).
  7. The requests will then be processed. The student(s) will get their welcome e-mail, which also contains the cluster access information, as soon as their account is ready. This happens usually within a day.
  8. You can see your students in the Nutzerkonteverwaltung and you can also extend their access from there. Remember that extensions are always for one year.

Prolonging a student as a supervisor

Prolongation of a student works analogously to adding a student. After adding the student again, the account gains access to the cluster for an other 12 month. Student’s data is untouched by this process.

Obtaining access: external user

External User can gain access to the Cluster if the following conditions are met:

  1. The external user needs a ZIMT account. The professor who is responsible for the external user, can request an account for external users at the Support Desk.
  2. The professor has to request cluster access for the external user. A informal e-mail to support@zimt.uni-siegen is sufficient.
  3. The external user has to fill out and sign our Terms of Use form. It is sufficient to send us a scanned copy as PDF file via e-mail. Important: The user has to enter his ZIMT account into the form, therefore the form can only be submitted, after the user received their ZIMT account. Incomplete or incorrectly filled forms will not be accepted.
  4. The user needs to create an SSH key-pair and send us their public key.

Changing your password

Caution: if you change your password on the cluster, the change will apply to all other services linked to this user account as well (e.g. Moodle, Webmail, eduroam, …). The password can also be changed using this link.

You can change your password in Linux with the command passwd.

If you enter passwd, you will first be asked for your current password. Once this has been entered correctly, you can enter the new password. You will then have to type it a second time to confirm it.

Output of passwd:

$ passwd
Ändern Passwort für Benutzer <user>.
Aktuelles Passwort: 
Geben Sie ein neues Passwort ein: 
Geben Sie das neue Passwort erneut ein: 
passwd: alle Authentifizierungs-Merkmale erfolgreich aktualisiert.

Note: The password will not be shown in the command line as you enter it, not even as stars.

Aktualisiert um 16:37 am 8. February 2021 von Gerd Pokorra