DACHS/Login: Difference between revisions

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== Username ==
== Username ==


If you want to use DACHS, you need to add a prefix to your local username.
If you want to use DACHS, you need to add a prefix to your local username: <code>prefix_username</code>.


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{| class="wikitable"
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For a full list of user names, you can check the [https://www.bwidm.de/hochschulen.php bwIDM Hochschulen page].
For a full list of user names, you can check the [https://www.bwidm.de/hochschulen.php bwIDM Hochschulen page].


Example:<br/>
'''Example:'''<br/>
If your local username for the University is <code>vwxyz1234</code> and you are a user from the University of Esslingen this would combine to: <code>es_vwxyz1234</code>.
If your local username for the University is <code>vwxyz1234</code> and you are a user from the University of Esslingen this would combine to: <code>es_vwxyz1234</code>.



== Hostnames ==
== Hostnames ==

Revision as of 00:09, 12 November 2024

Attention.svg

Access to DACHS is limited to IP addresses from the BelWü network. All home institutions of our current users are connected to BelWü, so if you are on your campus network (e.g. in your office or on the Campus WiFi) you should be able to connect to DACHS without restrictions. If you are outside one of the BelWü networks (e.g. at home), a VPN connection to the home institution or a connection to an SSH jump host at the home institution must be established first.

The login nodes of the DACHS cluster are the access points to the compute system, your $HOME directory and your workspaces. All users must log in through these nodes to submit jobs to the cluster.

Prerequisites for successful login:

You need to have


Login to the DACHS

Login to the DACHS is only possible with a Secure Shell (SSH) client for which you must know your username on the cluster and the hostname of the login nodes. For more general information on SSH clients, visit the SSH clients Guide.

Username

If you want to use DACHS, you need to add a prefix to your local username: prefix_username.

University Prefix
HS Aalen aa
HS Albstadt-Sigmaringen as
HS Esslingen es
HS Heilbronn hn
HS Karlsruhe hk
HTWG Konstanz ht
HS Mannheim mn
HS Offenburg of
HS Reutlingen hr
HfT-Stuttgart hs
THU-Ulm hu


For a full list of user names, you can check the bwIDM Hochschulen page.

Example:
If your local username for the University is vwxyz1234 and you are a user from the University of Esslingen this would combine to: es_vwxyz1234.

Hostnames

The system has two login nodes. The selection of the login node is done automatically. (TODO verify. How will this work?) If you are logging in multiple times, different sessions might run on different login nodes.

Login to DACHS:

Hostname Node type
login.hs-esslingen.de login to one of the two login nodes

In general, you should use automatic selection to allow us to balance the load over the two login nodes. If you need to connect to specific login nodes, you can use the following hostnames:

Hostname Node type
login1.hs-esslingen.de DACHS first login node
login2.hs-esslingen.de DACHS second login node

Host Keys

When you log in, you may receive the message The authenticity of host '<host address>' can't be established. along with the host key fingerprint. This is intended so you can verify the authenticity of the host you are connecting to. Before you continue you should verify, if this fingerprint matches one of the following:

Algorithm Fingerprint (SHA256)
RSA SHA256:TODO
ECDSA SHA256:TODO
ED25519 SHA256:TODO

Login with SSH command (Linux, Mac, Windows)

Most Unix and Unix-like operating systems like Linux, Mac OS and *BSD come with a built-in SSH client provided by the OpenSSH project. More recent versions of Windows 10 and Windows 11 using the Windows Subsystem for Linux (WSL) also come with a built-in OpenSSH client.

For login use one of the following ssh commands:

ssh <username>@login.hs-esslingen.de
ssh -l <username> login.hs-esslingen.de


TODO: Not sure if this will be available:

To run graphical applications, you can use the -X or -Y flag to ssh:

ssh -Y -l <username> login.hs-esslingen.de

For better performance, we recommend using VNC.

Login with graphical SSH client (Windows)

For Windows we suggest using MobaXterm for login and file transfer.

Start MobaXterm, fill in the following fields:

Remote name              : login.hs-esslingen.de
Specify user name        : <username>
Port                     : 22

After that click on 'ok'. Then a terminal will be opened and there you can enter your credentials.

Note: When using File transfer with MobaXterm version 23.6 the following configuration change has to be made: In the settings in the tab "SSH", change the option "SSH engine" from "<new>" to "<legacy>". Then restart MobaXterm

Login with Jupyterhub

TODO: will there be another URL for this?


Login takes place at:

More Information can be found here.


Login Example

To log in to DACHS, you must provide your service password. Proceed as follows:

  1. Use SSH for a login node.
  2. The system will ask for a one-time password Your OTP:. Please enter your OTP and confirm it with Enter/Return. If you do not have a second factor yet, please create one (see Registration/2FA).
  3. The system will ask you for your service password Password:. Please enter it and confirm it with Enter/Return. If you do not have a service password yet or have forgotten it, please create one (see Registration/Password).
  4. You will be greeted by the DACHS cluster, followed by a shell.
~ $ ssh -l es_vwxyz1234 login.hs-esslingen.de
(es_vwxyz1234@login.hs-esslingen.de) Your OTP: 123456
(es_vwxyz1234@login.hs-esslingen.de) Password: 
********************************************************************************
Last login: Thu Jul  7 18:09:43 2022 from login.hs-esslingen.de
********************************************************************************
[es_vwxyz1234@login1 ~]$ 

Troubleshooting

Nothing yet.


Allowed Activities on Login Nodes

Attention.svg

To guarantee usability for all the users of clusters you must not run your compute jobs on the login nodes. Compute jobs must be submitted to the queuing system. Any compute job running on the login nodes will be terminated without any notice. Any long-running compilation or any long-running pre- or post-processing of batch jobs must also be submitted to the queuing system.

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

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

TODO: We advise users to use interactive jobs for compute and memory intensive tasks like compiling.


Related Information