To gain access to the cluster, you need to do two things:

1. Have your user account activated for using scientific computing resources, and
2. set up a Secure Shell (SSH) connection. The first step is described on this page; details on SSH connections can be foundhere.

You log in to the cluster using your ZIMT ID.
The following section also explains how to change your password from the cluster.

Note: Since May 2020, password-based access has only been possible from the university network or the university VPN. Public-key authentication is required from all other networks. Details can be found under "Connecting."

Requesting Access as a Staff Member

As a staff member, you can request access yourself. To do so, follow these steps:

1. Log in to theuser account management system with your ZIMT ID.
2. Click “My Options” on the left.
3. Select the option “Scientific Computing Resources (OMNI)” by clicking the “Book Now” button.
4. Enter the required information here and confirm theterms of use.
5. Your request will now be processed. You will receive a welcome email with login information as soon as your account is activated. This usually happens the next day.

Requesting Access as a Student

Students can only use the cluster if they are authorized by a staff member (advisor). The advisor must have cluster access themselves. Access for students is limited to one year but can be renewed as often as desired and at any time for another year. This can also be done by another staff member, who will then be assigned as the student’s supervisor.

Requesting Access for Students as a Supervisor

As a staff member (advisor), you can grant students access to scientific computing resources in the user account management system. You only need the student’s email address.

To add a student, follow these steps:

1. Log in to theuser account management system with your ZIMT ID.
2. Click “My Options” on the left.
3. At the very bottom of the “My Options” page, you’ll find “Enable options that may incur fees for third parties.”
4. There, select “Scientific Computing Resources (OMNI) for Students/Staff” using the “Enter” button.
5. In the next step, add one or more students or staff members using their email addresses.
6. These individuals will then receive an email with an invitation to activate this option in the user account management system. There, they will provide the necessary information and confirm theterms of use.
7. These requests will now be processed further. Students will receive a welcome email with login information as soon as their account is activated. This usually happens the next day.
8. You can view your approvals in the user account management system. Approvals are always valid for only 12 months.

Extending Access for Students as a Supervisor

The renewal process is the same as submitting a new application. Once you submit a new application or send an invitation to a student, their access will be valid for an additional 12 months. The students’ files will be preserved.

Obtaining Access as an External User

External users can gain access to the cluster. To do so, the following requirements must be met:

1. External users need a ZIMT account. The person responsible for or supervising the external user (chair of a department, etc.) can request this through the ZIMT Support Desk.
2. The person responsible for or supervising the external user must request cluster access. To do so, simply send an informal email tosupport@zimt.uni-siegen.de.
3. The external user must sign the form containing ZIMT’s terms of use and send it to ZIMT. The signed form can be emailed as a scanned PDF file to support@zimt.uni-siegen.de or attached to an existing support ticket. 
   Important: The ZIMT account ID must be entered on the form. The form is therefore not complete until the external user has received their access credentials. Incomplete or incorrectly filled-out forms will be rejected.
4. The user must generate an SSH key pair and send the public key to ZIMT.

Changing Your Password:

Note: If you change your password on the cluster, this change will also apply to all other services linked to this user account (e.g., Moodle, Webmail, eduroam, …). You can also change your password in theuser account management system.

On Linux, you can change your password using the `passwd` command.

When you enter the`passwd` command, you will first be prompted for your current password. If the password is correct, you can enter the new password. You must repeat the new password to confirm it.

Output of `passwd`:

$ passwd
Changing password for user .
Current password: 
Enter a new password: 
Re-enter the new password: 
passwd: all authentication attributes successfully updated.

Note: Password entries on the command line are not displayed, not even as asterisks.