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Logging in

  • OpenSSH

  • MobaXterm: supports interactive shells and remote file transfers on Windows

  • FileZilla: supports remote file transfer on Windows/Linux/macOS

You can also use Jupyter.

SSH login process

After finishing the registration process, HoreKa is ready for SSH based login.

The login nodes of HoreKa are the access point to the compute system and to your HoreKa $HOME directory. HoreKa has 4 dedicated login nodes. All incoming connections are automatically distributed across all available login nodes for performance and stability reasons. This means that when you open multiple concurrent sessions on HoreKa, they will run on different physical computer systems.

Your username on HoreKa will be the one determined during the registration process.

Network access limitations

Please note that you have to be connected to an allowed network to access HoreKa. See the Network access limitations section for more details.

A connection to HoreKa can be established using the following SSH command:

$ ssh <UserID>@horeka.scc.kit.edu

If you are using OpenSSH (usually installed on Linux based systems) and you want to use a GUI-based application on HoreKa can be established by the command:

$ ssh -X <UserID>@horeka.scc.kit.edu

If you are in more than one project group, your home directory (the directory you see after login) will be the first project name. With the command

$ id

you can see all project groups you are in. Changing the project group can be done by the command

$ newgrp <new_project_group>

Changing the project group does not mean to change the accounting behaviour of your batch jobs. If you want to debit a specific account and a specific project group respectively you have to use the sbatch option -A (--account=...) when starting batch jobs.

Example login process

After the connection has been initiated, a successful login process will go through the following three steps:

  1. The system asks for a One-Time Password. Generate one using the Software or Hardware Token registered on FeLS (see 2-Factor Authentification) and enter it after the Your OTP: prompt.

  2. The systems asks for your service password. Enter it after the Password: prompt.

  3. You are greeted by the HoreKa banner followed by a shell.

The result should look like this:

Network access limitations

Access to HoreKa is limited to IP addresses from the campus networks of the home institutions of the current users. If you are on your campus network (e.g. in your office or on the campus WiFi), you should be able to connect to HoreKa without restrictions.

If you are outside of one of those networks (e.g. in your home office instead of in your campus office), a VPN connection to your home institution has to be established first.

If your home institution is not on the following allow list but should be, please contact the support channels.

List of currently allowed networks

  • KIT internal networks
  • All universities in Baden-Wurttemberg
  • Forschungszentrum Jülich
  • Forschungszentrum Dresden-Rossendorf
  • Hemholtz-Zentrum München (HMGU)
  • Deutsches Elektronensynchrotron (DESY)

Allowed activities on login nodes

The login nodes are shared with all other users. Therefore all activities on the login nodes are limited to primarily setting up your batch jobs. Compilation of your program code and short pre- and postprocessing runs are also allowed on the login nodes.

To guarantee usability for all users of HoreKa, you must not run your actual compute jobs on the login nodes. Compute jobs must be submitted to the batch system. Any compute job found to be running on the login nodes will be terminated without notice. Long-running compilation or any long-running pre- or postprocessing of batch jobs must also be submitted to the queueing system.

SSH Keys

In contrast to many other Linux-based systems, it is not possible to self-manage your SSH Keys by adding them to the ~/.ssh/authorized_keys file. Existing files will with this name are not evaluated on HoreKa.

SSH Keys have to be managed via FeLS instead. Please refer to the Using SSH Keys chapter for more information.


Last update: August 18, 2021