BwForCluster JUSTUS2 Login

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1 Login to JUSTUS 2

1.1 Prerequisites for login

  • You have registered your account at the registration server for JUSTUS 2.
  • You have set a service password for JUSTUS 2.
  • You have set up a time-based one-time password (TOTP) for the two factor authentication (2FA) log in.
  • Your IP is within the IP range of your university. Either you are working on a computer on your campus or you are connected via a virtual private network (VPN) to your university.
    • If you have an external IP (i.e. home office) and you are not connected via VPN to your university, you can not connect to JUSTUS 2. Please consult the documentation of your university how to connect to your university via VPN.

1.2 Login to JUSTUS 2

When all prerequisites are fulfilled you can access the bwForCluster JUSTUS 2 for Computational Chemistry and Quantum Sciences via ssh. Only the secure shell ssh is allowed for login.

From Linux machines, you can log in using

ssh <UserID>@justus2.uni-ulm.de

During log in you must enter the current TOTP value (6-digit number) created with help of the TOTP app on your smartphone and your service password.

To run graphical applications, you can use the -X flag to openssh:

ssh -X <UserID>@justus2.uni-ulm.de

For better performance on slow connections you should use e.g. VNC.


The bwForCluster Chemistry in Ulm has four dedicated login nodes. The selection of the login node is done automatically. If you are logging in multiple times, different sessions might run on different login nodes.

The names of the four login nodes are justus2-login01.rz.uni-ulm.de, justus2-login02.rz.uni-ulm.de, justus2-login03.rz.uni-ulm.de, justus2-login04.rz.uni-ulm.de.

These names can be used to access a specific one of the login nodes. In general, you should use justus2.uni-ulm.de to allow us to balance the load over the four login nodes.

1.3 About UserID / Username

<UserID> of the ssh command is a placeholder for your username at your home organization and a prefix denoting your organization. Prefixes and resulting user names are as follows:

Site Prefix Username
Freiburg fr fr_username
Heidelberg hd hd_username
Hohenheim ho ho_username
Karlsruhe ka ka_username
Konstanz kn kn_username
Mannheim ma ma_username
Stuttgart st st_username
Tübingen tu tu_username
Ulm ul ul_username

1.4 Allowed activities on login nodes

The login nodes are the access point to the compute system and its $HOME directory. The login nodes are shared with all the users of the cluster. Therefore, your activities on the login nodes are limited to primarily set up your batch jobs. Your activities may also be:

  • compilation of your program code and
  • short pre- and postprocessing of your batch jobs.

To guarantee usability for all users of the bwForCluster you must not run your compute jobs on the login nodes. Compute jobs must be submitted as Batch Jobs. Any compute job running on the login nodes will be terminated without any notice.

2 Further reading