Helix/Login

Access to bwForCluster Helix is limited to IP addresses within the BelWü network which connects universities and other scientific institutions in Baden-Württemberg. If your computer is in your University network (e.g. at your office), you should be able to connect to bwForCluster Helix without restrictions. If you are outside the BelWü network (e.g. at home), a VPN (virtual private network) connection to your University network must be established first. Please consult the VPN documentation of your University.

Login nodes are the access point to an HPC system, your $HOME directory and your workspaces. All users must log in to the login nodes to submit jobs to the compute nodes.

Prerequisites for successful login:

You need to have

• completed the 3-step bwForCluster registration procedure.
• set a service password for bwForCluster Helix.
• registered a token for the two factor authentication (2FA).

Username

If you want to use the bwForCluster Helix you need to add a prefix to your local username. For prefixes please refer to the Username Wiki.

Example:

• If your local username for the University is ab123 and you are a user from Heidelberg University this would combine to: hd_ab123.

Login to bwForCluster Helix

After registration bwForCluster Helix can be accessed via Secure Shell (SSH). Only SSH is allowed for login.

From Linux machines, you can log in using the following command:

ssh <UserID>@helix.bwservices.uni-heidelberg.de

To run graphical applications, you need to enable X11 forwarding with the -X option:

ssh -X <UserID>@helix.bwservices.uni-heidelberg.de

For SSH client programs with graphical user interfaces, fill in UserID and login server name accordingly. For Windows you can use PuTTY or MobaXterm. The later comes with an integrated X11 server which is necessary for the work with graphical applications.

The bwForCluster Helix has serveral login nodes. The selection of the login node is done automatically. If you log in multiple times, different sessions might run on different login nodes. In general, you should use the generic hostname given above to allow us to balance the load over the login nodes.

Allowed activities on login nodes

The login nodes are the access point to the compute system and to your $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 the 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 notice.