Wiss. Rechnen » Access
 

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 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.

Obtaining access: employees

University employees can request cluster access themselves. To do that you need to log in to the Nutzerkontenverwaltung with your ZIMT ID, click on “Meine Dienste” and then click the plus sign next to “High Performance Computing (HPC) – Linux cluster (HoRUS)”. Then follow the instructions. You will be asked to print a PDF form and have it signed by your supervisor.

After completing the process you will normally be given access within a few days.

Obtaining access: students

Students can only use the cluster if they are assigned a supervisor who has to be an employee that already has cluster access. HPC access for students has a limited duration, but the duration can be extended each semester.

As a supervisor, you can add, remove and prolong access for your students yourself. You need to do the following:

  1. Load the studentadmin module on the cluster:
    $ module load studentadmin
  2. Initialize Kerberos by entering the following command:
    $ kinit

    after which you will be asked to enter your password.

  3. Run one of the studentadmin scripts:
    hpc_user_add.sh     .... adds user to group 
    hpc_user_prolong.sh .... prolongs user in a group 
    hpc_user_remove.sh  .... removes user from group 
    hpc_user_list.sh    .... lists users in group
  4. Follow the instructions in the window that opens. In the following example hpc_user_add.sh is shown, the navigation in the other scripts works analogously.

    To select an option, press the space bar. The selected action is marked with an asterisk. Once the correct option is selected, you can proceed with Enter.

The account will have access immediately, but the home directory will only be created the next day and the student will not be able to do much before then.

Tips:

  • The expert mode of  hpc_user_add.sh allows you to select the group for the user (see Linux basics) this is only necessary in special cases. The default group for students is hpc-student.
  • If, when registering your student, you get an error message about missing permissions, you need to log into the Nutzerkontenverwaltung once, this will update your account to work with the Nutzerkontenverwaltung.

Changing your password

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.

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.

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 17:42 am 12. August 2018 von Jan Philipp Stephan